Once a contribution has been ported to a given version of the Drupal core API, the maintainer should create a branch that corresponds to the branch name used by core. This is not technically required, but is definitely recommended for responsible project maintainers.

These initial stable branches are similar to the branch names used by Drupal core branches, with the addition of the module's [Major] version number. For example, the initial release of a module compatible with Drupal 6 should be branched with: DRUPAL-6--1.

Historically, the Drupal Contributions repository supported 'partial' branch names like DRUPAL--4-7 and DRUPAL-5, treating them as synonyms for DRUPAL-4-7--1 and DRUPAL-5--1. Starting with the DRUPAL-6 core branch, code in the contributions repository must use fully-named branches, like DRUPAL-6--1 and DRUPAL-6--2.