As long as you use a valid WordPress.org username in the `Contributors:` tag in `readme.txt`, then yes: once the `readme.txt` is parsed by Extend/SVN, then the specified username *automagically* has SVN-commit access to the Plugin. Note: I know that it works for the **`Contribuors:`** tag, as I am such a contributor on a couple Plugins. If you're using a **`Collaborators:`** tag, I am unsure of how such a tag gets parsed. EDIT ---- And I mis-spoke somewhat. @Otto reminds me that committers must also be added, via the `plugins\plugin-name\advanced` page. So, props Otto; I had completely forgotten about that part! So, there's really no *automagic*. Go to `wordpress.org/plugins/plugin-name/advanced`, look for the **Committers** heading, add a WPORG username to the text field, and click "Add Committer".