Naming of system groups

[Joel Peshkin]

After discovering that the new system group, "admin" sometimes 
overlapped with an existing group on some sites, I would like to avoid 
this in the future.

I am considering renaming all system groups to have a prefix (either "_" 
or "bz_" so that "editusers" would become "_editusers" or 
"bz_editusers") if we have consensus that all system groups should be 
required to follow such a convention.

Opinions?