diff --git a/.circleci/config.yml b/.circleci/config.yml
index 333308bf2f..483269e7ce 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -37,11 +37,20 @@ jobs:
           at: ~/build
       - run:
           command: |
+            if (! git log -1 --pretty=%b | grep REL:) ; then
             chmod a+rX -R ~
             linkchecker -t 1 ~/build/site/
             # check external separately by pointing to all *html so no
             # failures for local file:/// -- yoh found no better way,
-            linkchecker -t 1 --check-extern --ignore-url 'file:///.*' --ignore-url https://fonts.gstatic.com ~/build/site/*html ~/build/site/*/*.html
+            linkchecker -t 1 --check-extern \
+              --ignore-url 'file:///.*' \
+              --ignore-url https://fonts.gstatic.com \
+              --ignore-url "https://github.com/bids-standard/bids-specification/(pull|tree)/.*" \
+              --ignore-url "https://github.com/[^/]*" \
+              ~/build/site/*html ~/build/site/*/*.html
+            else
+            echo "Release PR - do nothing"
+            fi
 
   build_docs_pdf:
     working_directory: ~/bids-specification/pdf_build_src
diff --git a/DECISION-MAKING.md b/DECISION-MAKING.md
index 4fb314900d..90012a90ab 100644
--- a/DECISION-MAKING.md
+++ b/DECISION-MAKING.md
@@ -2,8 +2,68 @@
 
 ## Introduction
 
-The Brain Imaging Data Structure (BIDS) community set out the following
-decision-making rules with the intention to:
+In October 2019, the BIDS community [voted](https://github.com/bids-standard/bids-specification/issues/355)
+to ratify a governance structure and to elect five members as a *Steering Group*
+to oversee the development and adoption of the standard.
+
+The document outlining our governance structure is hosted on the BIDS website:
+[https://bids.neuroimaging.io/governance.html](https://bids.neuroimaging.io/governance.html)
+
+In the following, we list the current members of subgroups detailed in the
+BIDS governance.
+
+**Steering Group**
+
+| Name                                                                 
+|------------------------------------------------------------------------------|
+| Guiomar Niso ([@guiomar](https://github.com/guiomar))                        |
+| Melanie Ganz ([@melanieganz](https://github.com/melanieganz))                |
+| Robert Oostenveld ([@robertoostenveld](https://github.com/robertoostenveld)) |
+| Russel Poldrack ([@poldrack](https://github.com/poldrack))                   |
+| Kristie Whitaker ([@KristieJane](https://github.com/KristieJane))            |
+
+**Maintainers Group**
+
+| Name                                                                           | Time commitment | Scope                 |
+|--------------------------------------------------------------------------------|-----------------|-----------------------|
+| Stefan Appelhoff ([@sappelhoff](https://github.com/sappelhoff))                | 5h/week         |                       |
+| Chris Markiewicz ([@effigies](https://github.com/effigies))                    | 5h/week         |                       |
+| Franklin Feingold ([@franklin-feingold](https://github.com/franklin-feingold)) | 5h/week         | Community development | 
+
+In addition to the [BIDS Governance](https://bids.neuroimaging.io/governance.html#bids-maintainers-group)
+classification of a maintainer, maintainers may declare a limited scope of responsibility.
+Such a scope can range from maintaining a modality supported in the specification to nurturing a
+welcoming BIDS community. 
+One or more scopes can be chosen by the maintainer and agreed upon by the Maintainers Group.
+A maintainer is primarily responsible for issues within their chosen scope(s), although
+contributions elsewhere are welcome, as well.
+
+**BEP Leads Group**
+
+Leaders of BIDS Extension Proposals are listed in the
+[table of BEPs](https://bids.neuroimaging.io/get_involved.html#extending-the-bids-specification).
+
+**Contributors Group**
+
+Contributors are listed in [Appendix I](https://bids-specification.readthedocs.io/en/stable/99-appendices/01-contributors.html)
+of the BIDS specification. Contributors who have not yet entered their name
+into this list are encouraged to edit the [Contributors WIKI page](https://github.com/bids-standard/bids-specification/wiki/Contributors)
+with their name, using the emojis listed in the WIKI to indicate their
+contributions.
+
+**Other groups**
+
+The following groups not listed in detail. Please learn more about these groups
+from the [governance document](https://bids.neuroimaging.io/governance.html).
+
+- BEP working groups
+- Advisory Group
+- BIDS Community
+
+## GitHub Workflow
+
+For the day-to-day work on the BIDS specification, we currently abide by the
+following rules with the intention to:
 
 - Strive for consensus.
 - Promote open discussions.
@@ -16,24 +76,6 @@ decision-making rules with the intention to:
 The rules outlined below are inspired by the [lazy consensus system used in the Apache Foundation](https://www.apache.org/foundation/voting.html)
 and heavily depends on [GitHub Pull Request Review system](https://help.github.com/articles/about-pull-requests/).
 
-## Definitions
-
-**Repository** - [https://github.com/bids-standard/bids-specification](https://github.com/bids-standard/bids-specification)
-
-**Contributor** - a person listed in the Appendix I: Contributors. The
-community decides on the content of this file using the same process as any
-other change to the Repository (see below) allowing the meaning of "Contributor"
-to evolve independently of the Decision-making rules.
-
-**Maintainer** - a Contributor responsible for the long term health of the
-project and the community. Maintainers have additional rights (see Rules)
-helping them to resolve conflicts and increase the pace of the development
-when necessary. Current Maintainers:
-
-| Name                                                            | Time commitment |
-|-----------------------------------------------------------------|-----------------|
-| Stefan Appelhoff ([@sappelhoff](https://github.com/sappelhoff)) | 5h/week         |
-
 ## Rules
 
 1. Every modification of the specification (including a correction of a typo,
diff --git a/README.md b/README.md
index e01c6f2c66..b681418fc3 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,7 @@
 [![Build Status](https://travis-ci.com/bids-standard/bids-specification.svg?branch=master)](https://travis-ci.com/bids-standard/bids-specification)
 [![CircleCI](https://circleci.com/gh/bids-standard/bids-specification.svg?style=svg)](https://circleci.com/gh/bids-standard/bids-specification)
 [![@BIDSstandard](http://img.shields.io/twitter/follow/bidsstandard.svg?style=social)](https://twitter.com/BIDSstandard)
-
+[![DOI](https://zenodo.org/badge/DOI/10.5281/zenodo.3686061.svg)](https://doi.org/10.5281/zenodo.3686061)
 
 <img src="./BIDS_logo/BIDS_logo_black_transparent_background_crop.png" alt="bids-logo" width="600"/>
 
diff --git a/Release_Protocol.md b/Release_Protocol.md
index c2dedcd475..580ea5574c 100644
--- a/Release_Protocol.md
+++ b/Release_Protocol.md
@@ -57,14 +57,14 @@ If the version preceding the `-dev` is not the target version, update the versio
 In the figure below, we update `v1.2.0-dev` to `v1.2.0`.
 ![dev-to-stable](release_images/site_name_release_1.2dev-1.2.png "dev-to-stable")
 
-Note: this will make our continuous integration ([CircleCI](https://circleci.com/)) fail. This fails because the URL of the new ReadTheDocs rendering has not been generated at this time. It will be generated once the GitHub release has been completed. 
+Note: this will make our continuous integration ([CircleCI](https://circleci.com/)) fail. This fails because the URL of the new ReadTheDocs rendering has not been generated at this time. It will be generated once the GitHub release has been completed.
 
 Synchronize the [Contributors appendix](https://github.com/bids-standard/bids-specification/blob/master/src/99-appendices/01-contributors.md)
 with the [Contributors wiki page](https://github.com/bids-standard/bids-specification/wiki/Contributors)
 to ensure all contributors are duly credited.
 Be sure not to remove credits if both have been edited.
 
-Please change the previous version links from GitHub to ReadTheDocs. 
+Please change the previous version links from GitHub to ReadTheDocs.
 In the figure below, we update v1.2.2.
 ![github-to-rtd](release_images/GitHub_to_RTD_spec_rendering.png "github-to-rtd")
 
@@ -118,7 +118,7 @@ $ git push rel/1.2.0
 
 ### 5. Set release date and merge
 
-On the day of release, please ensure the release branch aligns with the master branch. 
+On the day of release, please ensure the release branch aligns with the master branch.
 The current date should be added to/updated in the changelog in the form
 YYYY-MM-DD.
 The date should be placed after the link to the versioned URL.
@@ -131,7 +131,20 @@ For example:
 
 Verify that the pull request title matches "REL: vX.Y.Z" and merge the pull request.
 
-### 6. Tag the release
+### 6. Get the built PDF
+
+Upon each commit to the `master` branch, CircleCI builds a PDF version of the
+specification (see `.circleci/config.yml` and the `pdf_build_src` directory).
+
+So after merging the new "stable" version into `master`, wait for the CircleCI
+jobs to finish and then check the built PDF using this link:
+
+`https://circleci.com/api/v1.1/project/github/bids-standard/bids-specification/latest/artifacts/0/bids-spec.pdf?branch=master`
+
+Download the PDF and hold it ready for upload to our Zenodo archive. See the
+*Uploading the stable PDF to Zenodo* step below.
+
+### 7. Tag the release
 
 GitHub's release mechanism does not have all of the features we need, so manually tag the release
 in your local repository.
@@ -155,7 +168,7 @@ There are four components to the tag command:
 4. `upstream/master` instructs `git` to tag the most recent commit on the `master` branch of the
    `upstream` remote.
 
-### 7. Create a GitHub release
+### 8. Create a GitHub release
 
 Some GitHub processes may only trigger on a GitHub release, rather than a tag push.
 To make a GitHub release, go to the [Releases
@@ -177,10 +190,10 @@ Verify ReadTheDocs builds complete and publish. If needed, manually
 trigger [builds](https://readthedocs.org/projects/bids-specification/builds/)
 for `stable` and the most recent tag.
 
-### 8. Edit the mkdocs.yml file site_name to set a new development version
+### 9. Edit the mkdocs.yml file site_name to set a new development version
 
-Please submit a PR with the title `REL: <version>-dev`.
-This should be the first merged PR in the new version.
+Please commit to `master` with the title `REL: <version>-dev`.
+This should be the first commit in the new version.
 This process is illustrated below.
 
 ![stable-to-dev](release_images/site_name_release_1.2-1.3dev.png "stable-to-dev")
@@ -190,10 +203,24 @@ version of the next *intended* release, followed by `-dev`.
 For example, after the 1.3.0 release, either `1.3.1-dev` or `1.4.0-dev` would be reasonable, based
 on the expected next version.
 
-### 9. Sharing news of the release
+### 10. Uploading the stable PDF to Zenodo
+
+1. Open a private browser window
+1. Log into https://github.com with the `bids-maintenance` user (credentials
+   are available from the BIDS maintainer group)
+1. Open a new tab at https://zenodo.org and "log in via GitHub", you'll then
+   be on the `bids-maintenance` Zenodo account
+1. Navigate to the [archive of our BIDS specification PDFs](https://doi.org/10.5281/zenodo.3686061)
+1. Click on "add new version"
+1. For a new version, upload the new PDF, naming it consistently with the other
+   PDFs: `BIDS-Specification-vX.X.X.pdf` (replace `X.X.X` with the new version)
+1. Remove all other files from the upload
+1. Edit the following fields:
+    1. publication date
+    1. version
+1. Double check that everything is in order, then save and publish
+
+### 11. Sharing news of the release
 
 Please share news of the release on the [identified platforms](https://docs.google.com/spreadsheets/d/16SAGK3zG93WM2EWuoZDcRIC7ygPc5b7PDNGpFyC3obA/edit#gid=0).
 Please use our previous release posts as a guide.
-
-
-
diff --git a/mkdocs.yml b/mkdocs.yml
index 24acea42cf..5a2650f1ee 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -1,4 +1,4 @@
-site_name: Brain Imaging Data Structure v1.3.0-dev
+site_name: Brain Imaging Data Structure v1.3.1-dev
 theme:
     name: material
     custom_dir: theme_customizations/
@@ -31,6 +31,7 @@ nav:
         - Task events: 04-modality-specific-files/05-task-events.md
         - Physiological and other continuous recordings: 04-modality-specific-files/06-physiological-and-other-continuous-recordings.md
         - Behavioral experiments (with no MRI): 04-modality-specific-files/07-behavioral-experiments.md
+        - Genetic Descriptor: 04-modality-specific-files/08-genetic-descriptor.md
       - Longitudinal and multi-site studies: 05-longitudinal-and-multi-site-studies.md
       - BIDS Extension Proposals: 06-extensions.md
       - Appendix:
diff --git a/src/02-common-principles.md b/src/02-common-principles.md
index 0e66a45f93..a00d1e597c 100644
--- a/src/02-common-principles.md
+++ b/src/02-common-principles.md
@@ -6,21 +6,22 @@ The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD",
 "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be
 interpreted as described in [[RFC2119](https://www.ietf.org/rfc/rfc2119.txt)].
 
-Throughout this specification we use a list of terms. To avoid
+Throughout this specification we use a list of terms and abbreviations. To avoid
 misunderstanding we clarify them here.
 
-1.  Dataset - a set of neuroimaging and behavioral data acquired for a purpose
-    of a particular study. A dataset consists of data acquired from one or more
-    subjects, possibly from multiple sessions.
+1.  **Dataset** - a set of neuroimaging and behavioral data acquired for a
+    purpose of a particular study. A dataset consists of data acquired from one
+    or more subjects, possibly from multiple sessions.
 
-1.  Subject - a person or animal participating in the study.
+1.  **Subject** - a person or animal participating in the study.  Used
+    interchangeably with term **Participant**.
 
-1.  Session - a logical grouping of neuroimaging and behavioral data consistent
-    across subjects. Session can (but doesn't have to) be synonymous to a visit
-    in a longitudinal study. In general, subjects will stay in the scanner
-    during one session. However, for example, if a subject has to leave the
-    scanner room and then be re-positioned on the scanner bed, the set of MRI
-    acquisitions will still be considered as a session and match sessions
+1.  **Session** - a logical grouping of neuroimaging and behavioral data
+    consistent across subjects. Session can (but doesn't have to) be synonymous
+    to a visit in a longitudinal study. In general, subjects will stay in the
+    scanner during one session. However, for example, if a subject has to leave
+    the scanner room and then be re-positioned on the scanner bed, the set of
+    MRI acquisitions will still be considered as a session and match sessions
     acquired in other subjects. Similarly, in situations where different data
     types are obtained over several visits (for example fMRI on one day followed
     by DWI the day after) those can be grouped in one session. Defining multiple
@@ -28,34 +29,51 @@ misunderstanding we clarify them here.
     are planned and performed on all -or most- subjects, often in the case of
     some intervention between sessions (e.g., training).
 
-1.  Data acquisition - a continuous uninterrupted block of time during which a
-    brain scanning instrument was acquiring data according to particular
+1.  **Data acquisition** - a continuous uninterrupted block of time during which
+    a brain scanning instrument was acquiring data according to particular
     scanning sequence/protocol.
 
-1.  Data type - a functional group of different types of data. In BIDS we define
-    eight data types: func (task based and resting state functional MRI), dwi
-    (diffusion weighted imaging), fmap (field inhomogeneity mapping data such as
-    field maps), anat (structural imaging such as T1, T2, etc.), meg
-    (magnetoencephalography), eeg (electroencephalography), ieeg (intracranial
-    electroencephalography), beh (behavioral).
+1.  **Data type** - a functional group of different types of data. In BIDS we
+    define eight data types: `func` (task based and resting state functional MRI),
+    `dwi` (diffusion weighted imaging), `fmap` (field inhomogeneity mapping data
+    such as field maps), `anat` (structural imaging such as T1, T2, etc.), `meg`
+    (magnetoencephalography), `eeg` (electroencephalography), `ieeg` (intracranial
+    electroencephalography), `beh` (behavioral).
 
-1.  Task - a set of structured activities performed by the participant. Tasks
-    are usually accompanied by stimuli and responses, and can greatly vary in
-    complexity. For the purpose of this specification we consider the so-called
+1.  **Task** - a set of structured activities performed by the participant.
+    Tasks are usually accompanied by stimuli and responses, and can greatly vary
+    in complexity. For the purpose of this specification we consider the so-called
     "resting state" a task. In the context of brain scanning, a task is always
     tied to one data acquisition. Therefore, even if during one acquisition the
     subject performed multiple conceptually different behaviors (with different
     sets of instructions) they will be considered one (combined) task.
 
-1.  Event - a stimulus or subject response recorded during a task. Each event
-    has an onset time and duration. Note that not all tasks will have recorded
-    events (e.g., resting state).
+1.  **Event** - a stimulus or subject response recorded during a task. Each
+    event has an onset time and duration. Note that not all tasks will have
+    recorded events (e.g., “resting state”).
 
-1.  Run - an uninterrupted repetition of data acquisition that has the same
+1.  **Run** - an uninterrupted repetition of data acquisition that has the same
     acquisition parameters and task (however events can change from run to run
     due to different subject response or randomized nature of the stimuli). Run
     is a synonym of a data acquisition.
 
+1.  **`<index>`** - a numeric value, possibly prefixed with arbitrary number of
+    0s for consistent indentation, e.g., it is `01` in `run-01` following
+    `run-<index>` specification.
+
+1.  **`<label>`** - an alphanumeric value, possibly prefixed with arbitrary
+    number of 0s for consistent indentation, e.g., it is `rest` in `task-rest`
+    following `task-<label>` specification.
+
+1.  **`suffix`** - an alphanumeric value, located after the `key-value_` pairs (thus after
+    the final `_`), right before the **File extension**, e.g., it is `eeg` in
+    `sub-05_task-matchingpennies_eeg.vhdr`.
+
+1.  **File extension** - a portion of the the file name after the left-most
+    period (`.`) preceded by any other alphanumeric. For example, `.gitignore` does
+    not have a file extension, but the file extension of `test.nii.gz` is `.nii.gz`.
+    Note that the left-most period is included in the file extension.
+
 ## Compulsory, optional, and additional data and metadata
 
 The following standard describes a way of arranging data and writing down
@@ -264,8 +282,7 @@ additional meta information extracted from DICOM files in a sidecar JSON file
 (with the same filename as the `.nii[.gz]` file, but with a `.json` extension).
 Extraction of BIDS compatible metadata can be performed using [dcm2niix](https://github.com/rordenlab/dcm2niix)
 and [dicm2nii](http://www.mathworks.com/matlabcentral/fileexchange/42997-dicom-to-nifti-converter/content/dicm2nii.m)
-DICOM to NIfTI converters. A provided
-[validator](https://github.com/bids-standard/bids-validator)
+DICOM to NIfTI converters. The [BIDS-validator](https://github.com/bids-standard/bids-validator)
 will check for conflicts between the JSON file and the data recorded in the
 NIfTI header.
 
@@ -274,9 +291,13 @@ NIfTI header.
 Tabular data MUST be saved as tab delimited values (`.tsv`) files, i.e., CSV
 files where commas are replaced by tabs. Tabs MUST be true tab characters and
 MUST NOT be a series of space characters. Each TSV file MUST start with a header
-line listing the names of all columns (with the exception of physiological and
-other continuous acquisition data - see below for details). Names MUST be
-separated with tabs. String values containing tabs MUST be escaped using double
+line listing the names of all columns (with the exception of
+[physiological and other continuous recordings](04-modality-specific-files/06-physiological-and-other-continuous-recordings.md)).
+Names MUST be separated with tabs.
+It is RECOMMENDED that the column names in the header of the TSV file are
+written in [`snake_case`](https://en.wikipedia.org/wiki/Snake_case) with the
+first letter in lower case (e.g., `variable_name`, not `Variable_name`).
+String values containing tabs MUST be escaped using double
 quotes. Missing and non-applicable values MUST be coded as `n/a`. Numerical
 values MUST employ the dot (`.`) as decimal separator and MAY be specified
 in scientific notation, using `e` or `E` to separate the significand from the
@@ -340,8 +361,14 @@ format can be found here: [http://json.org/](http://json.org/). Several editors
 have built-in support for JSON syntax highlighting that aids manual creation of
 such files. An online editor for JSON with built-in validation is available at:
 [http://jsoneditoronline.org](http://jsoneditoronline.org). 
+It is RECOMMENDED that keys in a JSON file are written in [CamelCase](https://en.wikipedia.org/wiki/Camel_case)
+with the first letter in upper case (e.g., `SamplingFrequency`, not
+`samplingFrequency`). Note however, when a JSON file is used as an accompanying
+sidecar file for a [TSV file](#tabular-files), the keys linking a TSV column
+with their description in the JSON file need to follow the exact formatting
+as in the TSV file.
 
-Example:
+Example of a hypothetical `*_bold.json` file, accompanying a `*_bold.nii` file:
 
 ```JSON
 {
@@ -350,20 +377,38 @@ Example:
 }
 ```
 
+Example of a hypothetical `*_events.json` file, accompanying an
+`*_events.tsv` file. Note that the JSON file contains a key describing an
+*arbitrary* column `stim_presentation_side` in the TSV file it accompanies.
+See [task events section](04-modality-specific-files/05-task-events.md)
+for more information.
+
+```JSON
+{
+  "stim_presentation_side": {
+    "Levels": {
+      "1": "stimulus presented on LEFT side",
+      "2": "stimulus presented on RIGHT side"
+    }
+  }
+}
+```
+
 ## Participant names and other labels
 
-BIDS uses custom user-defined labels in several situations (naming of
-participants, sessions, acquisition schemes, etc.) Labels are strings and MUST
-only consist of letters (lower or upper case) and/or numbers. If numbers are
-used we RECOMMEND zero padding (e.g., `01` instead of `1` if you have more than
-nine subjects) to make alphabetical sorting more intuitive.
-
-Please note that a given label is distinct from the "prefix" it refers to. For
-example `sub-01` refers to the `sub` entity (a subject) with the label `01`.
-The `sub-` prefix is not part of the subject label, but must be included in file
-names (similarly to other key names). In contrast to other labels, `run` and
-`echo` labels MUST be integers. Those labels MAY include zero padding, but this
-is NOT RECOMMENDED to maintain their uniqueness.
+BIDS allows for custom user-defined `<label>`s and `<index>`es e.g.,
+for naming of participants, sessions, acquisition schemes, etc. Note
+that they MUST consist only of allowed characters as described in
+[Definitions](02-common-principles.md#definitions) above. In `<index>`es
+we RECOMMEND using zero padding (e.g., `01` instead of `1` if you have more than
+nine subjects) to make alphabetical sorting more intuitive. Note that
+zero padding SHOULD NOT be used to merely maintain uniqueness
+of `<index>`es.
+
+Please note that a given label or index is distinct from the "prefix"
+it refers to. For example `sub-01` refers to the `sub` entity (a
+subject) with the label `01`. The `sub-` prefix is not part of the subject
+label, but must be included in file names (similarly to other key names).
 
 ## Units
 
diff --git a/src/03-modality-agnostic-files.md b/src/03-modality-agnostic-files.md
index 309cd77caa..f15a0465e4 100644
--- a/src/03-modality-agnostic-files.md
+++ b/src/03-modality-agnostic-files.md
@@ -2,7 +2,11 @@
 
 ## Dataset description
 
-Template: `dataset_description.json` `README` `CHANGES`
+Templates:
+
+-   `dataset_description.json`
+-   `README`
+-   `CHANGES`
 
 ### `dataset_description.json`
 
@@ -68,10 +72,10 @@ Example:
 
 ```Text
 1.0.1 2015-08-27
- - Fixed slice timing information.
+  - Fixed slice timing information.
 
 1.0.0 2015-08-17
- - Initial release.
+  - Initial release.
 ```
 
 ## Participants file
@@ -81,29 +85,107 @@ Template:
 ```Text
 participants.tsv
 participants.json
-phenotype/<measurement_tool_name>.tsv
-phenotype/<measurement_tool_name>.json
 ```
 
-Optional: Yes
+The purpose of this RECOMMENDED file is to describe properties of participants
+such as age, sex, handedness etc.
+In case of single-session studies, this file has one compulsory column
+`participant_id` that consists of `sub-<label>`, followed by a list of optional
+columns describing participants.
+Each participant MUST be described by one and only one row.
+
+Commonly used *optional* columns in `participant.tsv` files are `age`, `sex`,
+and `handedness`. We RECOMMEND to make use of these columns, and
+in case that you do use them, we RECOMMEND to use the following values
+for them:
+
+-   `age`: numeric value in years (float or integer value)
+
+-   `sex`: string value indicating phenotypical sex, one of "male", "female",
+    "other"
+
+    -   for "male", use one of these values: `male`, `m`, `M`, `MALE`, `Male`
+
+    -   for "female", use one of these values: `female`, `f`, `F`, `FEMALE`,
+      ` Female`
 
-The purpose of this file is to describe properties of participants such as age,
-handedness, sex, etc. In case of single session studies this file has one
-compulsory column `participant_id` that consists of `sub-<label>`,
-followed by a list of optional columns describing participants. Each participant
-needs to be described by one and only one row.
+    -   for "other", use one of these values: `other`, `o`, `O`, `OTHER`,
+        `Other`
+
+-   `handedness`: string value indicating one of "left", "right",
+    "ambidextrous"
+
+    -   for "left", use one of these values: `left`, `l`, `L`, `LEFT`, `Left`
+
+    -   for "right", use one of these values: `right`, `r`, `R`, `RIGHT`,
+        `Right`
+
+    -   for "ambidextrous", use one of these values: `ambidextrous`, `a`, `A`,
+        `AMBIDEXTROUS`, `Ambidextrous`
+
+Throughout BIDS you can indicate missing values with `n/a` (i.e., "not
+available").
 
 `participants.tsv` example:
 
 ```Text
-participant_id  age sex group
-sub-control01 34  M control
-sub-control02 12  F control
-sub-patient01 33  F patient
+participant_id age sex handedness group
+sub-01 34 M right read
+sub-02 12 F right write
+sub-03 33 F n/a read
+```
+
+It is RECOMMENDED to accompany each `participants.tsv` file with a sidecar
+`participants.json` file to describe the TSV column names and properties of their values (see also
+the [section on tabular files](02-common-principles.md#tabular-files)).
+Such sidecar files are needed to interpret the data, especially so when
+optional columns are defined beyond `age`, `sex`, and `handedness`, such as
+`group` in this example, or when a different age unit is needed (e.g., gestational weeks).
+If no `units` is provided for age, it will be assumed to be in years relative to date of birth. 
+
+`participants.json` example:
+
+```JSON
+{
+    "age": {
+        "Description": "age of the participant",
+        "Units": "years"
+    },
+    "sex": {
+        "Description": "sex of the participant as reported by the participant",
+        "Levels": {
+            "M": "male",
+            "F": "female"
+        }
+    },    
+    "handedness": {
+        "Description": "handedness of the participant as reported by the participant",
+        "Levels": {
+            "left": "left",
+            "right": "right"
+        }
+    },
+    "group": {
+        "Description": "experimental group the participant belonged to",
+        "Levels": {
+            "read": "participants who read an inspirational text before the experiment",
+            "write": "participants who wrote an inspirational text before the experiment"
+        }
+    }
+}
 ```
 
 ## Phenotypic and assessment data
 
+Template:
+
+```Text
+phenotype/<measurement_tool_name>.tsv
+phenotype/<measurement_tool_name>.json
+```
+
+Optional: Yes
+
 If the dataset includes multiple sets of participant level measurements (for
 example responses from multiple questionnaires) they can be split into
 individual files separate from `participants.tsv`.
diff --git a/src/04-modality-specific-files/01-magnetic-resonance-imaging-data.md b/src/04-modality-specific-files/01-magnetic-resonance-imaging-data.md
index 5e652f866b..625187c6a0 100644
--- a/src/04-modality-specific-files/01-magnetic-resonance-imaging-data.md
+++ b/src/04-modality-specific-files/01-magnetic-resonance-imaging-data.md
@@ -91,7 +91,7 @@ first "effective" echo and the center of the last "effective" echo.
 Useful for multimodal co-registration with MEG, (S)EEG, TMS, etc.
 
 | Field name                    | Definition                                                                                                                                                                                                                                                                                                                                     |
-| --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |------------------------------------------------------------------------------- |
+| --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
 | AnatomicalLandmarkCoordinates | RECOMMENDED. Key:value pairs of any number of additional anatomical landmarks and their coordinates in voxel units (where first voxel has index 0,0,0) relative to the associated anatomical MRI, (e.g. `{"AC": [127,119,149], "PC": [128,93,141], "IH": [131,114,206]}, or {"NAS": [127,213,139], "LPA": [52,113,96], "RPA": [202,113,91]}`). |
 
 #### Institution information
@@ -102,9 +102,10 @@ Useful for multimodal co-registration with MEG, (S)EEG, TMS, etc.
 | InstitutionAddress          | RECOMMENDED. The address of the institution in charge of the equipment that produced the composite instances. Corresponds to DICOM Tag 0008, 0081 `InstitutionAddress`.               |
 | InstitutionalDepartmentName | RECOMMENDED. The department in the institution in charge of the equipment that produced the composite instances. Corresponds to DICOM Tag 0008, 1040 `Institutional Department Name`. |
 
-When adding additional metadata please use the camelcase version of
+When adding additional metadata please use the CamelCase version of
 [DICOM ontology terms](https://scicrunch.org/scicrunch/interlex/dashboard)
-whenever possible.
+whenever possible. See also
+[recommendations on JSON files](../02-common-principles.md#keyvalue-files-dictionaries).
 
 ### Anatomy imaging data
 
@@ -272,10 +273,10 @@ JSON file.
 #### Required fields
 
 | Field name     | Definition                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
-|-----------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
 | RepetitionTime | REQUIRED. The time in seconds between the beginning of an acquisition of one volume and the beginning of acquisition of the volume following it (TR). Please note that this definition includes time between scans (when no data has been acquired) in case of sparse acquisition schemes. This value needs to be consistent with the `pixdim[4]` field (after accounting for units stored in `xyzt_units` field) in the NIfTI header. This field is mutually exclusive with `VolumeTiming` and is derived from DICOM Tag 0018, 0080 and converted to seconds. |
 | VolumeTiming   | REQUIRED. The time at which each volume was acquired during the acquisition. It is described using a list of times (in JSON format) referring to the onset of each volume in the BOLD series. The list must have the same length as the BOLD series, and the values must be non-negative and monotonically increasing. This field is mutually exclusive with `RepetitionTime` and `DelayTime`. If defined, this requires acquisition time (TA) be defined via either `SliceTiming` or `AcquisitionDuration` be defined.                                        |
-| TaskName       | REQUIRED. Name of the task. No two tasks should have the same name. Task label (`task-`) included in the file name is derived from this field by removing all non alphanumeric (`[a-zA-Z0-9]`) characters. For example task name `faces n-back` will corresponds to task label `facesnback`. A RECOMMENDED convention is to name resting state task using labels beginning with `rest`.                                                                                                                                                                        |
+| TaskName       | REQUIRED. Name of the task. No two tasks should have the same name. The task label included in the file name is derived from this TaskName field by removing all non-alphanumeric (`[a-zA-Z0-9]`) characters. For example TaskName `faces n-back` will correspond to task label `facesnback`. A RECOMMENDED convention is to name resting state task using labels beginning with `rest`.                                                                                                                                                                       |
 
 For the fields described above and in the following section, the term "Volume"
 refers to a reconstruction of the object being imaged (e.g., brain or part of a
diff --git a/src/04-modality-specific-files/02-magnetoencephalography.md b/src/04-modality-specific-files/02-magnetoencephalography.md
index 12f1c7888e..fbe4865655 100644
--- a/src/04-modality-specific-files/02-magnetoencephalography.md
+++ b/src/04-modality-specific-files/02-magnetoencephalography.md
@@ -42,11 +42,18 @@ MAY be included alongside the MEG data; examples are provided below.
 This template is for MEG data of any kind, including but not limited to
 task-based, resting-state, and noise recordings. If multiple Tasks were
 performed within a single Run, the task description can be set to
-`task-multitask`. The \_meg.json SHOULD contain details on the Tasks. Some
-manufacturers data storage conventions use folders which contain data files of
-various nature: e.g., CTF’s .ds format, or BTi/4D. Please refer to
-[Appendix VI](../99-appendices/06-meg-file-formats.md) for examples from a
-selection of MEG manufacturers.
+`task-multitask`. The \_meg.json SHOULD contain details on the Tasks.
+
+Some manufacturers' data storage conventions use folders which contain data
+files of various nature: for example, CTF's `.ds` format, or BTi/4D.
+Yet other manufacturers split their files once they exceed a certain size
+limit. For example Neuromag/Elekta/Megin, which can produce several files
+for a single recording. Both `some_file.fif` and `some_file-1.fif` would
+belong to a single recording. In BIDS, the `split` entity is RECOMMENDED to
+deal with split files.
+Please refer to [Appendix VI](../99-appendices/06-meg-file-formats.md) for
+general information on how to deal with such manufacturer specifics and to see
+more examples.
 
 The `proc` label is analogous to `rec` for MR and denotes a variant of a file
 that was a result of particular processing performed on the device. This is
@@ -59,9 +66,9 @@ actually be exploited.
 
 Generic fields MUST be present:
 
-| Field name | Definition                                                                                                                                                                                                                  |
-| ---------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
-| TaskName   | REQUIRED. Name of the task (for resting state use the `rest` prefix). Different Tasks SHOULD NOT have the same name. The Task label is derived from this field by removing all non alphanumeric (`[a-zA-Z0-9]`) characters. |
+| Field name | Definition                                                                                                                                                                                                                                                                                                                              |
+|------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| TaskName   | REQUIRED. Name of the task (for resting state use the `rest` prefix). No two tasks should have the same name. The task label included in the file name is derived from this TaskName field by removing all non-alphanumeric (`[a-zA-Z0-9]`) characters. For example TaskName `faces n-back` will correspond to task label `facesnback`. |
 
 SHOULD be present: For consistency between studies and institutions, we
 encourage users to extract the values of these fields from the actual raw data.
diff --git a/src/04-modality-specific-files/03-electroencephalography.md b/src/04-modality-specific-files/03-electroencephalography.md
index 414ae54071..a409960036 100644
--- a/src/04-modality-specific-files/03-electroencephalography.md
+++ b/src/04-modality-specific-files/03-electroencephalography.md
@@ -89,9 +89,9 @@ be specified.
 
 Generic fields MUST be present:
 
-| Field name | Definition                                                                                                                                                                                                                  |
-| --------------------------------------------------------------------------------------| -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
-| TaskName   | REQUIRED. Name of the task (for resting state use the `rest` prefix). Different Tasks SHOULD NOT have the same name. The Task label is derived from this field by removing all non alphanumeric (`[a-zA-Z0-9]`) characters. |
+| Field name | Definition                                                                                                                                                                                                                                                                                                                              |
+|------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| TaskName   | REQUIRED. Name of the task (for resting state use the `rest` prefix). No two tasks should have the same name. The task label included in the file name is derived from this TaskName field by removing all non-alphanumeric (`[a-zA-Z0-9]`) characters. For example TaskName `faces n-back` will correspond to task label `facesnback`. |
 
 SHOULD be present: For consistency between studies and institutions, we
 encourage users to extract the values of these fields from the actual raw data.
diff --git a/src/04-modality-specific-files/04-intracranial-electroencephalography.md b/src/04-modality-specific-files/04-intracranial-electroencephalography.md
index b383ad338f..e7e65517d1 100644
--- a/src/04-modality-specific-files/04-intracranial-electroencephalography.md
+++ b/src/04-modality-specific-files/04-intracranial-electroencephalography.md
@@ -23,8 +23,8 @@ Template:
 sub-<label>/
   [ses-<label>]/
     ieeg/
-      sub-<label>[_ses-<label>]_task-<task_label>[_run-<index>]_ieeg.<manufacturer_specific_extension>
-      sub-<label>[_ses-<label>]_task-<task_label>[_run-<index>]_ieeg.json
+      sub-<label>[_ses-<label>]_task-<label>[_run-<index>]_ieeg.<manufacturer_specific_extension>
+      sub-<label>[_ses-<label>]_task-<label>[_run-<index>]_ieeg.json
 ```
 
 The iEEG community uses a variety of formats for storing raw data, and there is
@@ -70,7 +70,7 @@ Note the RecordingType, which depends on whether the data stream on disk is inte
 ### Terminology: Electrodes vs. Channels
 
 For proper documentation of iEEG recording metadata it is important to
-understand the difference between electrode and channel: An iEEG electrode
+understand the difference between electrode and channel: an iEEG electrode
 is placed on or in the brain, whereas a channel is the combination of the analog
 differential amplifier and analog-to-digital converter that result in a
 potential (voltage) difference that is stored in the iEEG dataset. We employ the
@@ -102,9 +102,9 @@ please avoid using ad hoc wording.
 
 Generic fields MUST be present:
 
-| Field name         | Definition                                                                                                                                                                                                                                                                                                                                                                                                                |
-| --------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
-| TaskName           | REQUIRED. Name of the task (for resting state use the "rest" prefix). No two tasks should have the same name. Task label is derived from this field by removing all non alphanumeric (`[a-zA-Z0-9]`) characters. Note this does not have to be a "behavioral task" that subjects perform, but can reflect some information about the conditions present when the data was acquired (e.g., "rest", "sleep", or "seizure"). |
+| Field name | Definition                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
+|------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| TaskName   | REQUIRED. Name of the task (for resting state use the "rest" prefix). No two tasks should have the same name. The task label included in the file name is derived from this TaskName field by removing all non-alphanumeric (`[a-zA-Z0-9]`) characters. For example TaskName `faces n-back` will correspond to task label `facesnback`. Note this does not have to be a "behavioral task" that subjects perform, but can reflect some information about the conditions present when the data was acquired (e.g., "rest", "sleep", or "seizure"). |
 
 SHOULD be present: For consistency between studies and institutions, we
 encourage users to extract the values of these fields from the actual raw data.
diff --git a/src/04-modality-specific-files/05-task-events.md b/src/04-modality-specific-files/05-task-events.md
index 99df84d406..01bdec5fa8 100644
--- a/src/04-modality-specific-files/05-task-events.md
+++ b/src/04-modality-specific-files/05-task-events.md
@@ -45,7 +45,8 @@ the first volume.
 
 An arbitrary number of additional columns can be added. Those allow describing
 other properties of events that could be later referred in modelling and
-hypothesis extensions of BIDS.
+hypothesis extensions of BIDS. Note that any additional columns in a TSV file
+SHOULD be documented in an accompanying JSON sidecar file.
 
 In case of multi-echo task run, a single `_events.tsv` file will suffice for all
 echoes.
diff --git a/src/04-modality-specific-files/07-behavioral-experiments.md b/src/04-modality-specific-files/07-behavioral-experiments.md
index 83c2018384..769109b885 100644
--- a/src/04-modality-specific-files/07-behavioral-experiments.md
+++ b/src/04-modality-specific-files/07-behavioral-experiments.md
@@ -5,22 +5,22 @@ Template:
 ```Text
 sub-<label>/[ses-<label>/]
     beh/
-        sub-<label>[_ses-<label>]_task-<task_name>_events.tsv
-        sub-<label>[_ses-<label>]_task-<task_name>_events.json
-        sub-<label>[_ses-<label>]_task-<task_name>_beh.tsv
-        sub-<label>[_ses-<label>]_task-<task_name>_beh.json
-        sub-<label>[_ses-<label>]_task-<task_name>_physio.tsv.gz
-        sub-<label>[_ses-<label>]_task-<task_name>_physio.json
-        sub-<label>[_ses-<label>]_task-<task_name>_stim.tsv.gz
-        sub-<label>[_ses-<label>]_task-<task_name>_stim.json
+        sub-<label>[_ses-<label>]_task-<label>_events.tsv
+        sub-<label>[_ses-<label>]_task-<label>_events.json
+        sub-<label>[_ses-<label>]_task-<label>_beh.tsv
+        sub-<label>[_ses-<label>]_task-<label>_beh.json
+        sub-<label>[_ses-<label>]_task-<label>_physio.tsv.gz
+        sub-<label>[_ses-<label>]_task-<label>_physio.json
+        sub-<label>[_ses-<label>]_task-<label>_stim.tsv.gz
+        sub-<label>[_ses-<label>]_task-<label>_stim.json
 ```
 
 In addition to logs from behavioral experiments performed along imaging data
 acquisitions one can also include data from experiments performed outside of the
-scanner. The results of those experiments can be stored in the beh folder using
+scanner. The results of those experiments can be stored in the `beh` folder using
 the same formats for event timing (`_events.tsv`), metadata (`_events.json`),
 physiological (`_physio.tsv.gz`, `_physio.json`) and other continuous recordings
 (`_stim.tsv.gz`, `_stim.json`) as for tasks performed during MRI acquisitions.
 Additionally, events files that do not include the mandatory `onset` and
-`duration` columns can still be included, but should be labelled `_beh.tsv`
+`duration` columns can still be included, but should be labeled `_beh.tsv`
 rather than `_events.tsv`.
diff --git a/src/04-modality-specific-files/08-genetic-descriptor.md b/src/04-modality-specific-files/08-genetic-descriptor.md
new file mode 100644
index 0000000000..ad24b06fb4
--- /dev/null
+++ b/src/04-modality-specific-files/08-genetic-descriptor.md
@@ -0,0 +1,117 @@
+# Genetic Descriptor
+
+Support for genetic descriptors was developed as a [BIDS Extension
+Proposal](../06-extensions.md#bids-extension-proposals).
+The extension was primarily developed by Cyril Pernet and Clara Moreau with
+contributions from Tom Nichols and Jessica Turner.
+
+Genetic data are typically stored in dedicated repositories,
+separate from imaging data.
+A genetic descriptor links a BIDS dataset to associated genetic data,
+potentially in a separate repository,
+with details of where to find the genetic data and the type of data available.
+
+## Dataset Description
+
+Genetic descriptors are encoded as an additional, OPTIONAL entry in the
+[`dataset_description.json`](../03-modality-agnostic-files.md#dataset_descriptionjson)
+file.
+
+Datasets linked to a genetic database entry include the following REQUIRED or OPTIONAL
+`dataset_description.json` keys (a dot in the key name denotes a key in a subdictionary):
+
+| Field name           | Definition                                                                     |
+|----------------------|--------------------------------------------------------------------------------|
+| Genetics.Dataset     | REQUIRED. URI where data can be retrieved.                                     |
+| Genetics.Database    | OPTIONAL. URI of database where the dataset is hosted.                         |
+| Genetics.Descriptors | OPTIONAL. List of relevant descriptors (*e.g.*, journal articles) for dataset. |
+
+Example:
+
+```JSON
+{
+  "Name": "Human Connectome Project",
+  "BIDSVersion":  "1.3.0",
+  "License": "CC0",
+  "Authors": ["1st author", "2nd author"],
+  "Funding": ["P41 EB015894/EB/NIBIB NIH HHS/United States"],
+  "Genetics": {
+     "Dataset": "https://www.ncbi.nlm.nih.gov/projects/gap/cgi-bin/study.cgi?study_id=phs001364.v1.p1",
+     "Database": "https://www.ncbi.nlm.nih.gov/gap/",
+     "Descriptors": ["https://doi.org/10.1016/j.neuroimage.2013.05.041"]
+     }
+}
+```
+
+## Subject naming and Participants file
+
+If the same participants have different identifiers in the genetic and imaging datasets,
+the column `genetic_id` SHOULD be added to the `participants.tsv` file to associate
+the BIDS participant with a subject in the `Genetics.Dataset` referred to in the
+`dataset_description.json` file.
+
+Information about the presence/absence of specific genetic markers MAY be duplicated
+in the `participants.tsv` file by adding optional columns (like `idh_mutation` in the
+example below).
+Note that optional columns MUST be further described in an accompanying
+`participants.json` file as described in
+[Tabular files](../02-common-principles.md#tabular-files).
+
+`participants.tsv` example:
+
+```Text
+participant_id	age	sex	group	genetic_id	idh_mutation
+sub-control01	34	M	control	124587	yes
+sub-control02	12	F	control	548936	yes
+sub-patient01	33	F	patient	489634	no
+```
+
+## Genetic Information
+
+Template:
+
+```Text
+genetic_info.json
+```
+
+The `genetic_info.json` file describes the genetic information available in the
+`participants.tsv` file and/or the genetic database described in
+`dataset_description.json`.
+Datasets containing the `Genetics` field in `dataset_description.json` or the
+`genetic_id` column in `participants.tsv` MUST include this file with the following
+fields:
+
+| Field name                                                  | Definition                                                                                                                                                                                                                                                                               |
+|-------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| GeneticLevel                                                | REQUIRED. String. Describes the level of analysis. Values MUST be one of `Genetic`, `Genomic`, `Epigenomic`, `Transcriptomic`, `Metabolomic`, or `Proteomic`.                                                                                                                            |
+| AnalyticalApproach                                          | OPTIONAL. String or list of strings. Methodology or methodologies used to analyse the GeneticLevel. Values MUST be taken from the [database of Genotypes and Phenotypes (dbGaP)][gapsolr] under /Study/Molecular Data Type, for instance `SNP Genotypes (Array)` or `Methylation (CpG)`. |
+| SampleOrigin                                                | REQUIRED. String. Describes from which tissue the genetic information was extracted. Values MUST be one of `blood`, `saliva`, `brain`, `csf`, `breast milk`, `bile`, `amniotic fluid`, `other biospecimen`.                                                                              |
+| TissueOrigin                                                | OPTIONAL. String. Describes the type of tissue analyzed for SampleOrigin `brain`. Values MUST be one of `gray matter`, `white matter`, `csf`, `meninges`, `macrovascular` or `microvascular`.                                                                                            |
+| BrainLocation                                               | OPTIONAL. String. Refers to the location in space of the `TissueOrigin`. Values may be an MNI coordinate, a label taken from the [Allen Brain Atlas][allen], or layer to refer to layer-specific gene expression, which can also tie up with laminar fMRI.                               |
+| CellType                                                    | OPTIONAL. String. Describes the type of cell analyzed. Values SHOULD come from the [cell ontology][ontology].                                                                                                                                                                            |
+
+To ensure dataset description consistency, we recommend following [Multi-omics approaches to disease](https://genomebiology.biomedcentral.com/articles/10.1186/s13059-017-1215-1) by Hasin et al. 2017 to determine the `GeneticLevel:`
+
+-   `Genetic`: data report on a single genetic location (typically directly in the `participants.tsv` file)
+-   `Genomic`:  data link to participants' genome (multiple genetic locations)
+-   `Epigenomic`: data link to participants' characterization of reversible modifications of DNA
+-   `Transcriptomic`: data link to participants RNA levels
+-   `Metabolomic`: data link to participants' products of cellular metabolic functions
+-   `Proteomic`: data link to participants peptides and proteins quantification
+
+`genetic_info.json` example:
+
+```JSON
+{
+  "GeneticLevel": "Genomic",
+  "AnalyticalApproach": ["Whole Genome Sequencing", "SNP/CNV Genotypes"],
+  "SampleOrigin": "brain",
+  "TissueOrigin": "gray matter",
+  "CellType":  "neuron",
+  "BrainLocation": "[-30 -15 10]"
+}
+```
+
+[allen]: http://atlas.brain-map.org/atlas?atlas=265297125&plate=112360888&structure=4392&x=40348.15104166667&y=46928.75&zoom=-7&resolution=206.60&z=3
+[ontology]: http://obofoundry.org/ontology/cl.html
+[gapsolr]: https://www.ncbi.nlm.nih.gov/gap/advanced_search/
diff --git a/src/99-appendices/01-contributors.md b/src/99-appendices/01-contributors.md
index 50a4fc908a..64acc3a96a 100644
--- a/src/99-appendices/01-contributors.md
+++ b/src/99-appendices/01-contributors.md
@@ -84,6 +84,7 @@ your name is not listed, please add it.
 -   International Neuroinformatics Coordinating Facility 💵📋
 -   Andrew Janke 📖💻
 -   Mainak Jas 📖💻
+-   Alexander Jones 💻🐛
 -   David Keator 📖
 -   James Kent 💬💻
 -   Gregory Kiar 📖💻🎨🔧
@@ -134,6 +135,7 @@ your name is not listed, please add it.
 -   Pradeep Reddy Raamana 💻🔧
 -   Vasudev Raguram 💻🎨📖🔧
 -   Nick F. Ramsey 📖
+-   Kay Robbins 💻📖🐛
 -   Alex Rockhill 📖🔧
 -   Ariel Rokem 📖
 -   Matt Sanderson 📖💻
diff --git a/src/99-appendices/04-entity-table.md b/src/99-appendices/04-entity-table.md
index 11e485f9dd..ade3287c11 100644
--- a/src/99-appendices/04-entity-table.md
+++ b/src/99-appendices/04-entity-table.md
@@ -10,23 +10,23 @@ file type are denoted. Entity formats indicate whether the value is alphanumeric
 A general introduction to entities is given in the section on
 [file name structure](../02-common-principles.md#file-name-structure)
 
-| Entity                                                                                         | Subject       | Session       | Task           | Acquisition   | Contrast Enhancing Agent | Reconstruction | Phase-Encoding Direction | Run           | Corresponding modality | Echo           | Recording           | Processed (on device) | Space           |
-| :--------------------------------------------------------------------------------------------- | :------------ | :------------ | :------------- | :------------ | :----------------------- | :------------- | :----------------------- | :------------ | :--------------------- | :------------- | :------------------ | :-------------------- | :---------------|
-| Format                                                                                         | `sub-<label>` | `ses-<label>` | `task-<label>` | `acq-<label>` | `ce-<label>`             | `rec-<label>`  | `dir-<label>`            | `run-<index>` | `mod-<label>`          | `echo-<index>` | `recording-<label>` | `proc-<label>`        | `space-<label>` |
-| anat<br>(T1w T2w T1rho T1map T2map T2star FLAIR FLASH PD PDmap PDT2 inplaneT1 inplaneT2 angio) | REQUIRED      | OPTIONAL      |                | OPTIONAL      | OPTIONAL                 | OPTIONAL       |                          |               |                        |                |                     |                       |                 |
-| anat<br>(defacemask)                                                                           | REQUIRED      | OPTIONAL      |                | OPTIONAL      | OPTIONAL                 | OPTIONAL       |                          |               | OPTIONAL               |                |                     |                       |                 |
-| func<br>(bold cbv phase sbref events)                                                          | REQUIRED      | OPTIONAL      | REQUIRED       | OPTIONAL      | OPTIONAL                 | OPTIONAL       | OPTIONAL                 | OPTIONAL      |                        | OPTIONAL       |                     |                       |                 |
-| func<br>(physio stim)                                                                          | REQUIRED      | OPTIONAL      | REQUIRED       | OPTIONAL      |                          | OPTIONAL       |                          | OPTIONAL      |                        |                | OPTIONAL            | OPTIONAL              |                 |
-| dwi<br>(dwi bvec bval)                                                                         | REQUIRED      | OPTIONAL      |                | OPTIONAL      |                          |                | OPTIONAL                 | OPTIONAL      |                        |                |                     |                       |                 |
-| fmap<br>(phasediff phase1 phase2 magnitude1 magnitude2 magnitude fieldmap)                     | REQUIRED      | OPTIONAL      |                | OPTIONAL      |                          |                |                          | OPTIONAL      |                        |                |                     |                       |                 |
-| fmap<br>(epi)                                                                                  | REQUIRED      | OPTIONAL      |                | OPTIONAL      | OPTIONAL                 |                | REQUIRED                 | OPTIONAL      |                        |                |                     |                       |                 |
-| beh<br>(events stim physio)                                                                    | REQUIRED      | OPTIONAL      | REQUIRED       |               |                          |                |                          |               |                        |                |                     |                       |                 |
-| meg<br>                                                                                        | REQUIRED      | OPTIONAL      | REQUIRED       | OPTIONAL      |                          |                |                          | OPTIONAL      |                        |                |                     | OPTIONAL              |                 |
-| eeg<br>                                                                                        | REQUIRED      | OPTIONAL      | REQUIRED       | OPTIONAL      |                          |                |                          | OPTIONAL      |                        |                |                     |                       |                 |
-| ieeg<br>                                                                                       | REQUIRED      | OPTIONAL      | REQUIRED       | OPTIONAL      |                          |                |                          | OPTIONAL      |                        |                |                     |                       |                 |
-| channels<br>(meg/eeg/ieeg)                                                                     | REQUIRED      | OPTIONAL      | REQUIRED       |               |                          |                |                          | OPTIONAL      |                        |                |                     |                       |                 |
-| headshape<br>(meg)                                                                             | REQUIRED      | OPTIONAL      |                | OPTIONAL      |                          |                |                          |               |                        |                |                     |                       | OPTIONAL        |
-| markers<br>(meg)                                                                               | REQUIRED      | OPTIONAL      | OPTIONAL       | OPTIONAL      |                          |                |                          |               |                        |                |                     |                       | OPTIONAL        |
-| photo<br>(meg/eeg/ieeg)                                                                        | REQUIRED      | OPTIONAL      |                | OPTIONAL      |                          |                |                          |               |                        |                |                     |                       |                 |        
-| electrodes<br>(eeg/ieeg)                                                                       | REQUIRED      | OPTIONAL      |                | OPTIONAL      |                          |                |                          |               |                        |                |                     |                       | OPTIONAL        |
-| events<br>(meg/eeg/ieeg)                                                                       | REQUIRED      | OPTIONAL      | REQUIRED       |               |                          |                |                          | OPTIONAL      |                        |                |                     |                       |                 |        
+| Entity                                                                                         | Subject       | Session       | Task           | Acquisition   | Contrast Enhancing Agent | Reconstruction | Phase-Encoding Direction | Run           | Corresponding modality | Echo           | Recording           | Processed (on device) | Space           | Split           |
+| :--------------------------------------------------------------------------------------------- | :------------ | :------------ | :------------- | :------------ | :----------------------- | :------------- | :----------------------- | :------------ | :--------------------- | :------------- | :------------------ | :-------------------- | :---------------| :-------------- |
+| Format                                                                                         | `sub-<label>` | `ses-<label>` | `task-<label>` | `acq-<label>` | `ce-<label>`             | `rec-<label>`  | `dir-<label>`            | `run-<index>` | `mod-<label>`          | `echo-<index>` | `recording-<label>` | `proc-<label>`        | `space-<label>` | `split-<index>` |
+| anat<br>(T1w T2w T1rho T1map T2map T2star FLAIR FLASH PD PDmap PDT2 inplaneT1 inplaneT2 angio) | REQUIRED      | OPTIONAL      |                | OPTIONAL      | OPTIONAL                 | OPTIONAL       |                          |               |                        |                |                     |                       |                 |                 |
+| anat<br>(defacemask)                                                                           | REQUIRED      | OPTIONAL      |                | OPTIONAL      | OPTIONAL                 | OPTIONAL       |                          |               | OPTIONAL               |                |                     |                       |                 |                 |
+| func<br>(bold cbv phase sbref events)                                                          | REQUIRED      | OPTIONAL      | REQUIRED       | OPTIONAL      | OPTIONAL                 | OPTIONAL       | OPTIONAL                 | OPTIONAL      |                        | OPTIONAL       |                     |                       |                 |                 |
+| func<br>(physio stim)                                                                          | REQUIRED      | OPTIONAL      | REQUIRED       | OPTIONAL      |                          | OPTIONAL       |                          | OPTIONAL      |                        |                | OPTIONAL            | OPTIONAL              |                 |                 |
+| dwi<br>(dwi bvec bval)                                                                         | REQUIRED      | OPTIONAL      |                | OPTIONAL      |                          |                | OPTIONAL                 | OPTIONAL      |                        |                |                     |                       |                 |                 |
+| fmap<br>(phasediff phase1 phase2 magnitude1 magnitude2 magnitude fieldmap)                     | REQUIRED      | OPTIONAL      |                | OPTIONAL      |                          |                |                          | OPTIONAL      |                        |                |                     |                       |                 |                 |
+| fmap<br>(epi)                                                                                  | REQUIRED      | OPTIONAL      |                | OPTIONAL      | OPTIONAL                 |                | REQUIRED                 | OPTIONAL      |                        |                |                     |                       |                 |                 |
+| beh<br>(events stim physio)                                                                    | REQUIRED      | OPTIONAL      | REQUIRED       |               |                          |                |                          |               |                        |                |                     |                       |                 |                 |
+| meg<br>                                                                                        | REQUIRED      | OPTIONAL      | REQUIRED       | OPTIONAL      |                          |                |                          | OPTIONAL      |                        |                |                     | OPTIONAL              |                 | OPTIONAL        |
+| eeg<br>                                                                                        | REQUIRED      | OPTIONAL      | REQUIRED       | OPTIONAL      |                          |                |                          | OPTIONAL      |                        |                |                     |                       |                 |                 |
+| ieeg<br>                                                                                       | REQUIRED      | OPTIONAL      | REQUIRED       | OPTIONAL      |                          |                |                          | OPTIONAL      |                        |                |                     |                       |                 |                 |
+| channels<br>(meg/eeg/ieeg)                                                                     | REQUIRED      | OPTIONAL      | REQUIRED       |               |                          |                |                          | OPTIONAL      |                        |                |                     |                       |                 |                 |
+| headshape<br>(meg)                                                                             | REQUIRED      | OPTIONAL      |                | OPTIONAL      |                          |                |                          |               |                        |                |                     |                       | OPTIONAL        |                 |
+| markers<br>(meg)                                                                               | REQUIRED      | OPTIONAL      | OPTIONAL       | OPTIONAL      |                          |                |                          |               |                        |                |                     |                       | OPTIONAL        |                 |
+| photo<br>(meg/eeg/ieeg)                                                                        | REQUIRED      | OPTIONAL      |                | OPTIONAL      |                          |                |                          |               |                        |                |                     |                       |                 |                 |        
+| electrodes<br>(eeg/ieeg)                                                                       | REQUIRED      | OPTIONAL      |                | OPTIONAL      |                          |                |                          |               |                        |                |                     |                       | OPTIONAL        |                 |
+| events<br>(meg/eeg/ieeg)                                                                       | REQUIRED      | OPTIONAL      | REQUIRED       |               |                          |                |                          | OPTIONAL      |                        |                |                     |                       |                 |                 |        
diff --git a/src/99-appendices/06-meg-file-formats.md b/src/99-appendices/06-meg-file-formats.md
index de35a4acc5..98d0abd617 100644
--- a/src/99-appendices/06-meg-file-formats.md
+++ b/src/99-appendices/06-meg-file-formats.md
@@ -88,32 +88,35 @@ sub-control01_ses-001_task-rest_run-01_proc-sss_meg.fif
 sub-control01_ses-001_task-rest_run-01_proc-sss_meg.json
 ```
 
-In the case of data runs exceeding 2Gb, the data is stored in two separate
-files:
+In the case of long data recordings that exceed a file size of 2Gb, the `.fif`
+files are conventionally split into multiple parts. For example:
 
 ```Text
-sub-control01_ses-001_task-rest_run-01_meg.fif
-sub-control01_ses-001_task-rest_run-01_meg-1.fif
+some_file.fif
+some_file-1.fif
 ```
 
-Each of these two files has a pointer to the next file. In some software
-applications, like [MNE](https://www.martinos.org/mne/stable/index.html), one
-can simply specify the name of the first file, and data will be read in both
-files via this pointer. For this reason, it is RECOMMENDED to rename and write
-back the file once read, to avoid the persistence of a pointer associated with
-the old file name.
+Each of these files has an internal pointer to the next file.
+This is important when renaming these split recordings to the BIDS convention.
+Instead of a simple renaming, files should be read in and saved under their new
+names with dedicated tools like [MNE](https://mne.tools), which will ensure
+that not only the file names, but also the internal file pointers will be
+updated.
 
-Naming convention:
+It is RECOMMENDED that `.fif` files with multiple parts use the `split-<index>`
+entity to indicate each part.
+
+Example:
 
 ```Text
-sub-control01_ses-001_task-rest_run-01_part-01_meg.fif
-sub-control01_ses-001_task-rest_run-01_part-02_meg.fif
+sub-control01_ses-001_task-rest_run-01_split-01_meg.fif
+sub-control01_ses-001_task-rest_run-01_split-02_meg.fif
 ```
 
-More about the Neuromag/Elekta/MEGIN data organization at:
-[http://www.fieldtriptoolbox.org/getting_started/neuromag](http://www.fieldtriptoolbox.org/getting_started/neuromag)
-And BabyMEG :
-[http://www.fieldtriptoolbox.org/getting_started/babysquid](http://www.fieldtriptoolbox.org/getting_started/babysquid)
+More information can be found under the following links:
+
+-   [Neuromag/Elekta/MEGIN data organization](http://www.fieldtriptoolbox.org/getting_started/neuromag)
+-   [BabyMEG](http://www.fieldtriptoolbox.org/getting_started/babysquid)
 
 ## BTi/4D neuroimaging
 
diff --git a/src/99-appendices/08-coordinate-systems.md b/src/99-appendices/08-coordinate-systems.md
index bc6807a038..8b3f3afa1c 100644
--- a/src/99-appendices/08-coordinate-systems.md
+++ b/src/99-appendices/08-coordinate-systems.md
@@ -71,18 +71,11 @@ detailed extensive descriptions of these EEG coordinate systems on the
 Restricted keywords for the `XXXCoordinateSystem` field in the
 `coordsystem.json` file for EEG datasets:
 
--   `BESA`: Although natively this is a spherical coordinate system, the
-    electrode positions should be expressed in Cartesian coordinates, with a RAS
-    orientation. The X axis is the T8-T7 line, positive at T8. The Y axis is the
-    Oz-Fpz line, positive at Fpz. The origin of the sphere fitted to the
-    electrodes is approximately 4 cm above the point between the ears.
-
 -   `Captrak`: RAS orientation and the origin between the ears
 
 Note that the short descriptions above do not capture all details, There are
 detailed extensive descriptions of these EEG coordinate systems on the
-[FieldTrip toolbox web page](http://www.fieldtriptoolbox.org/faq/how_are_the_different_head_and_mri_coordinate_systems_defined)
-and on the [BESA wiki](http://wiki.besa.de/index.php?title=Electrodes_and_Surface_Locations#Coordinate_systems).
+[FieldTrip toolbox web page](http://www.fieldtriptoolbox.org/faq/how_are_the_different_head_and_mri_coordinate_systems_defined).
 
 ## iEEG Specific Coordinate Systems
 
diff --git a/src/CHANGES.md b/src/CHANGES.md
index 6e57254212..f108303607 100644
--- a/src/CHANGES.md
+++ b/src/CHANGES.md
@@ -2,8 +2,30 @@
 
 ## [Unreleased](https://github.com/bids-standard/bids-specification/tree/HEAD)
 
+-   \[INFRA] linkchecker - ignore github pull and tree URLs [#477](https://github.com/bids-standard/bids-specification/pull/477) ([yarikoptic](https://github.com/yarikoptic))
+-   \[MISC] Maintainers - `Scope` responsibility [#467](https://github.com/bids-standard/bids-specification/pull/467) ([franklin-feingold](https://github.com/franklin-feingold))
+-   \[FIX] Align tables in MRI section [#465](https://github.com/bids-standard/bids-specification/pull/465) ([sappelhoff](https://github.com/sappelhoff))
+-   \[FIX] Drop `\_part-` reference from example, introduce `\_split-` entity [#460](https://github.com/bids-standard/bids-specification/pull/460) ([sappelhoff](https://github.com/sappelhoff))
+-   \[FIX] clarify participants tsv+json with examples and recommendations [#459](https://github.com/bids-standard/bids-specification/pull/459) ([sappelhoff](https://github.com/sappelhoff))
+-   \[FIX] Remove BESA from list of restricted keywords of EEG coordsystems [#457](https://github.com/bids-standard/bids-specification/pull/457) ([sappelhoff](https://github.com/sappelhoff))
+-   \[INFRA] add steps for release protocol (PDF upload) [#455](https://github.com/bids-standard/bids-specification/pull/455) ([sappelhoff](https://github.com/sappelhoff))
+-   \[FIX] Add reference to PDF on front page of specification [#452](https://github.com/bids-standard/bids-specification/pull/452) ([nicholst](https://github.com/nicholst))
+-   \[INFRA] Add conditional for link-checking releases [#451](https://github.com/bids-standard/bids-specification/pull/451) ([franklin-feingold](https://github.com/franklin-feingold))
+-   \[FIX] unordered list formatting in BEP018 [#449](https://github.com/bids-standard/bids-specification/pull/449) ([sappelhoff](https://github.com/sappelhoff))
+-   REL: 1.3.1-dev [#448](https://github.com/bids-standard/bids-specification/pull/448) ([franklin-feingold](https://github.com/franklin-feingold))
+-   \[FIX] fix inconsistencies for task label between sections [#446](https://github.com/bids-standard/bids-specification/pull/446) ([Remi-Gau](https://github.com/Remi-Gau))
+-   \[FIX] update DECISION-MAKING.md document with new governance [#441](https://github.com/bids-standard/bids-specification/pull/441) ([sappelhoff](https://github.com/sappelhoff))
+-   \[ENH] Add `res` and `den` keywords to indicate resolution of resampled data [#301](https://github.com/bids-standard/bids-specification/pull/301) ([oesteban](https://github.com/oesteban))
+-   \[ENH] Add Glossary of terms/abbreviations used in the specification [#152](https://github.com/bids-standard/bids-specification/pull/152) ([yarikoptic](https://github.com/yarikoptic))
+
+## [v1.3.0](https://github.com/bids-standard/bids-specification/tree/v1.3.0) (2020-04-14)
+
+-   \[INFRA] add zenodo badge to README [#447](https://github.com/bids-standard/bids-specification/pull/447) ([sappelhoff](https://github.com/sappelhoff))
+-   Added contributors from VisLab [#444](https://github.com/bids-standard/bids-specification/pull/444) ([VisLab](https://github.com/VisLab))
+-   FIX: Clarify  snake_case+CamelCase in TSV+JSON [#442](https://github.com/bids-standard/bids-specification/pull/442) ([sappelhoff](https://github.com/sappelhoff))
 -   \[FIX] Eliminate web/online-specific language [#437](https://github.com/bids-standard/bids-specification/pull/437) ([nicholst](https://github.com/nicholst))
 -   \[INFRA] ensure build_docs_pdf CircleCI job runs last [#436](https://github.com/bids-standard/bids-specification/pull/436) ([sappelhoff](https://github.com/sappelhoff))
+-   REL: v1.3.0 [#435](https://github.com/bids-standard/bids-specification/pull/435) ([franklin-feingold](https://github.com/franklin-feingold))
 -   \[INFRA] Add issue templates for GitHub [#434](https://github.com/bids-standard/bids-specification/pull/434) ([sappelhoff](https://github.com/sappelhoff))
 -   \[INFRA] Get latest PDF build from CircleCI artifacts [#433](https://github.com/bids-standard/bids-specification/pull/433) ([sappelhoff](https://github.com/sappelhoff))
 -   \[INFRA] Update release protocol [#432](https://github.com/bids-standard/bids-specification/pull/432) ([franklin-feingold](https://github.com/franklin-feingold))
@@ -15,6 +37,7 @@
 -   \[INFRA] fix heading of auto changelog to be a markdown header [#417](https://github.com/bids-standard/bids-specification/pull/417) ([sappelhoff](https://github.com/sappelhoff))
 -   REL: 1.3.0-dev [#413](https://github.com/bids-standard/bids-specification/pull/413) ([franklin-feingold](https://github.com/franklin-feingold))
 -   ENH: Add OPTIONAL EthicsApprovals field to dataset description [#412](https://github.com/bids-standard/bids-specification/pull/412) ([effigies](https://github.com/effigies))
+-   \[ENH] BEP 018 - Genetic Information [#395](https://github.com/bids-standard/bids-specification/pull/395) ([effigies](https://github.com/effigies))
 
 ## [v1.2.2](https://github.com/bids-standard/bids-specification/tree/v1.2.2) (2020-02-12)
 
diff --git a/src/index.md b/src/index.md
index 731f10e2c6..3cb10529d8 100644
--- a/src/index.md
+++ b/src/index.md
@@ -6,4 +6,4 @@ To get started, [check out the introduction](01-introduction.md). If you'd like
 more information on how to adapt your own datasets to match the BIDS
 specification, we recommend exploring the [bids-specification starter kit](https://github.com/bids-standard/bids-starter-kit).
 
-For an overview of the BIDS ecosystem, visit the [BIDS homepage](https://bids.neuroimaging.io).
+For an overview of the BIDS ecosystem, visit the [BIDS homepage](https://bids.neuroimaging.io).  The entire specification can also be [downloaded as PDF](https://doi.org/10.5281/zenodo.3686061).