Does the distinction between TC and RC need to be in the name? How
about
C1 < C2 < C3 ...
with possibly an "R" suffix if the number of blocker bugs is 0, like
C1 < C2 < C3R < ...
This way they're alphabetical. There are also other side effects of
the
distinction between TC and RC such as having two separate releng
tickets, two
separate categories in the wiki, etc. and maybe some of those are
unnecessary as
well.
I was about to propose exactly the same:
build 1 < build 2 < build 3 RC < build 4 < build 5 RC
How we actually name the builds is a small detail (e.g. B1, B2, B3.RC), but it is
alphabetic and we can have much more builds this way if we need it without making things
more complicated. We mark some builds/composes as RC if it satisfies the criterion.