Preferred SVN layout?

Hi, I am noticing that some of the projects in svn have a "master" directory while others have the codename for the release of that distro. This has me wandering what's the preferred way to organize svn.

Ark doesn't apply a codename and is doing packages for it's upcoming release. The patches in the past with KDE3 would change occaisionally with each 3.x release (e.g. 3.0 patches probably wouldn't work with 3.4).

Considering this, I'm thinking maybe have a Master where the most recent patches and rpm spec go, and copy that over to a release (e.g. 2011.1 for this year, 2012.1 for next year) each time we release.