This page tracks a couple of notes on the build system environment. First of all, here's a couple of bookmarks for you:
First of all, build targets include a platform specific base (such as "Enterprise Linux 6"), it's stream (ergo, EL-6.1, EL-6.2), as well as any option value that this build target might provide (ergo, EL-6.1-Ruby-1.9.1-devel, EL-6.1-Ruby-1.9.1-stable). Whatever the naming convention does turn out to be –nothing of such is set in stone yet–, it is very important we allow such to be consistent all across the board.
Tag inheritance is majorly important if you think of each inherited tag as the basis of a tag.