Well folks, based on how utterly and completely limited it was before...
THE ONE-SIG-A-TURN RULE IS GONE! BE AFRAID! BE HAPPY! BE SOMETHING!
In it's place, however, is a slightly different system; this being that the total levels of the sigs you use in a turn can't add up to anything over 6.
To clarify, in one turn you can use:
One level 5, and one level 1
Two level 2s, and two level 1s
One level 4, and one level 2
Etc, etc. If the levels add up to something under 6, YOU'RE GOLDEN.
(PS: Yes, this does mean that you can flood the registration area if you've added in a 'Bypass the One-sig-a-turn-rule' clause to your sig. Free edits FTW.)