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Reword Notes & UIDs concept (#16202)
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- Note that Kubernetes UIDs are UUIDs
- Don't mention container name in Name concept (it could mislead
  readers)
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sftim authored and k8s-ci-robot committed Oct 14, 2019
1 parent 1393c49 commit 1ab3558
Showing 1 changed file with 18 additions and 5 deletions.
23 changes: 18 additions & 5 deletions content/en/docs/concepts/overview/working-with-objects/names.md
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{{% capture overview %}}

All objects in the Kubernetes REST API are unambiguously identified by a Name and a UID.
Each object in your cluster has a [_Name_](#names) that is unique for that type of resource.
Every Kubernetes object also has a [_UID_](#uids) that is unique across your whole cluster.

For non-unique user-provided attributes, Kubernetes provides [labels](/docs/user-guide/labels) and [annotations](/docs/concepts/overview/working-with-objects/annotations/).
For example, you can only have one Pod named “myapp-1234”, but you can have one Pod
and one Deployment that are each named “myapp-1234”.

See the [identifiers design doc](https://git.k8s.io/community/contributors/design-proposals/architecture/identifiers.md) for the precise syntax rules for Names and UIDs.
For non-unique user-provided attributes, Kubernetes provides [labels](/docs/concepts/overview/working-with-objects/labels/) and [annotations](/docs/concepts/overview/working-with-objects/annotations/).

{{% /capture %}}

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{{< glossary_definition term_id="name" length="all" >}}

By convention, the names of Kubernetes resources should be up to maximum length of 253 characters and consist of lower case alphanumeric characters, `-`, and `.`, but certain resources have more specific restrictions.
Kubernetes resources can have names up to 253 characters long. The characters allowed in names are: digits (0-9), lower case letters (a-z), `-`, and `.`.

For example, here’s the configuration file with a Pod name as `nginx-demo` and a Container name as `nginx`:
Here’s an example manifest for a Pod named `nginx-demo`.

```yaml
apiVersion: v1
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- containerPort: 80
```
{{< note >}}
Some resource types have additional restrictions on their names.
{{< /note >}}
## UIDs
{{< glossary_definition term_id="uid" length="all" >}}
Kubernetes UIDs are universally unique identifiers (also known as UUIDs).
UUIDs are standardized as ISO/IEC 9834-8 and as ITU-T X.667.
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{{% capture whatsnext %}}
* Read about [labels](/docs/concepts/overview/working-with-objects/labels/) in Kubernetes.
* See the [Identifiers and Names in Kubernetes](https://git.k8s.io/community/contributors/design-proposals/architecture/identifiers.md) design document.
{{% /capture %}}

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