I'll give you a brief rundown of how it all works, and how it's changed in the 20 years I've been in the industry. This is in an effort to both inform, and to hopefully keep you out of a courtroom at some point:
There are three basic sets of rules for every high school cheer team:
American Association of Cheerleading Coaches and Administrators (AACCA): The AACCA publishes the safety guidelines enforced at UCA/NCA nationals. The AACCA guidelines are also the legal standard by which you will be judged should someone get hurt and choose to sue you. If you were to be taken to court, someone from AACCA would be called as an expert witness to testify whether you were negligent or contributory to the injury. So the AACCA guidelines include such things as teaching proper progressions; wearing appropriate footwear, etc. Along with the typical "no 2 1/2 high pyramids." If you aren't following these guidelines, you could be potentially liable for an injury if your failure to do so is felt to have contributed to the injury. You can find AACCA guidelines at
Cheerleading Safety News & Resources - CheerSafe or
AACCA Cheerleading Safety Education and Risk Management
National Federation of High School Sports (NFHS or "Federation"): I am almost positive, but admit to not having 100% certainty that every state high school athletic association is a member of the NFHS. As such, every high school basketball team in the country, assuming their state athletic associations are willing to sanction the contest, can play any other high school basketball team in the country without confusion about nitpicky rules. Because most high school sports associations play major sports by the NFHS rules, they also adopt the NFHS safety rules as the guidelines for their cheer teams
Twenty years ago, there were subtle, but costly differences between the AACCA and the NFHS. For example, for several years the "yo-yo" dismount was legal in AACCA but not in NFHS. In the last four or five years, there has been a steady movement to have the rules aligned. It should be noted, though, that AACCA has the ability to make changes, if necessary, must more quickly than NFHS. NFHS only meets once a year to look at potential changes.
The last set of guidelines are very location-specific and govern the competition format itself. Most every form of cheer competition has adopted the 2 1/2 minute mixed cheer/music routine, but there are still a few obscure formats in existence. Up until the Kentucky High School Athletic Association took over competitive cheerleading a few years back, the Kentucky Association of Pep Organization Sponsors was still supporting both the 2 1/2 minute routine and the "traditional" routine. Traditional, at one time, included a non-gymnastic cheer (no stunting/tumbling), a normal cheer, and a dance. It was BRUTAL to watch.