Originally posted by AlboMalapropFoozer
FWIW, the USCF classifies G/10 up to G/29 as Quick Chess. G/31 and above is classified as Standard Chess. Interestingly, G/30 can be rated under either. A player's Quick Chess rating is calculated independently of their Standard Chess rating. The USCF does not rate games played at a time control faster than G/10.
This used to be the classification; however, a couple years ago they changed these to do two different things.
1) Quick Chess is now G/5-G/60.
2) Standard Chess is now G/30 or longer.
This had two effects; one, you could now hold rated blitz tournaments if you wanted to, and two, some events are dual rated.
http://www.uschess.org/ratings/info/time.html - has all the USCF info, although it neglects to mention that short "standard" games can also be rated as quick.