Other architectures: ARM, PowerPC, AArch64, etc...
32-bits only behavior (i386 or higher)
64-bits only behavior (also known as amd64)
Related to an Android-specific behavior (but not Linux)
Related to a BSD-specific behavior (FreeBSD, OpenBSD, DragonflyBSD, excluding OSX / iOS)
Related to an iOS-specific behavior (also include derived platforms, e.g. WatchOS or TvOS)
Related to a Linux-specific behavior (regardless of distribution)
Related to a Mac OSX-specific behavior (excluding iOS derivatives)
Related to a POSIX-specific behavior (e.g. Linux/Mac/Solaris...)
Related to a Windows-specific behavior (regardless of version)
Used to work in a previous version, but not anymore
A major issue that is a major roadblock for other issues or projects
A bug that is neither a blocker nor a regression
Things that are not fundamental bugs, things that can be worked around easily, enhancements
Issues or PR that are trivial to resolve (typos, minor documentation, simple refactoring)
Things don't work as they were intended to, or the way they were intended to work doesn't make sense
An improvement to an existing functionality