Internet Content Rating Association's content labeling system, based on W3C's PICS rating protocol. RSACi comes from "RSAC for the Internet", RSAC comes from "Recreational Software Advisory Council", now part of IRCA.
RSACi ratings rate the site (or individual page or resource) with four categories, each with number from 0 to 4. The categories are Nudity, Sex, Language and Violence.
Example RSACi PICS label (from a site I had the displeasure of rating today):
(PICS-1.1 "http://www.rsac.org/ratingsv01.html" l gen true
comment "RSACi North America Server"
r (n 1 s 2 v 3 l 1))
This would translate to "revealing attire, clothed sexual touching, death to human beings" (well, one guy got scorched in a story, so there...) and "mild expletives". (damn! =)
More information available at ICRA's home page at