Chapter 5. Version numbers and ABIs

The version that Linus or a stable series maintainer uses for a release. Currently Linus will use the version format: 4.x[-rcy]. Stable series maintainers use the version format: 4.x.y.

The version used in a Debian package. Following Debian policy, it should follow the format upstreamversion-debianrevision. However, for an upstream release candidate, the string '-rc' must be replaced with '~rc' so that it will be recognised as an earlier version than the following release.

This is the first part of the kernel version string. In official kernel packages it follows the format upstreamversion+release[.serial]. It is changed for every new package version; either the upstream version changes or the serial number is added or incremented.

In older releases (before Debian 13) this version follows the format upstreamversion-serial, and the 3rd component of the upstream version is always set to 0.

This is the version that appears in kernel messages, filenames, package names and the output of 'uname -r'. In official kernel packages it follows the format abiname[-featureset]-flavour.