For ITAA events, we use the US Archery / World Archery (FITA) rules for equipment classes and age divisions.
The USA Archery Event Reference Guide is a great intro and refresher for how to prepare for an event.
The World Archery Rules are available here
Bowman (up to and including the year of your 12th birthday)
Cub (up to and including the year of your 14th birthday)
Cadet (up to and including the year of your 17th birthday)
Junior (up to and including the year of your 20th birthday)
Senior — everyone else. (Anyone can always choose to compete in the Senior age division)
Masters 50+ — (available the year of your 50th birthday)
(Masters 55+) — The ITAA also holds a Masters 55+ division, which is not a formal US Archery division
(Masters 65+) The ITAA also holds a Masters 65+ division, which is not a formal US Archery division
Recurve (Olympic Style)
Compound Fingers (masters+ ages only)
Barebow (senior+ ages only)
Traditional Longbow (senior only)
Modern Longbow (senior only)
Traditional Recurve (senior only)
Crossbow (senior only) This equipment type is not available at most ITAA events, due to host venue restrictions
For various safety and historical reasons, US Archery events have a dress code. Event attendees are encouraged to adhere to it. Participants are required to adhere to it.
The full dress code is described here.