Two more things:
 1) Python 2 doc used to use the func(arg[, optional1[, optional2]]) notation, and with Python 3 we switched to func(arg, optional1=default1, optional2=default2).  The latter is also used in Python 2 now, and the [] are still there in Python 3 in some places;
 2) If you are going to fix it, you can probably backport the fix from py3k with "hg diff Doc/library/re.rst -c 106ee4eb5970";