North American Cup (all types)
Division I National Championships
Wheelchair National Championships
The July Challange
All of them.
Additionally, country colors are required on the pant legs for: Senior Junior and Cadet World Championships
Senior World Cup competitions(individual and team events)
Senior Zonal Championships (individual and team events)
"Fencers' clothing may be of different colours, apart from black."
Something like (m.25.3) is a rulebook citation. There are three main books: Technical rules (t.) Organization rules (o.) and Material rules. (m.)
The Fencing Officials Commission has stated that:
"Masks may feature colored designs, on condition that they are approved by the Fencing Officials Commission at least 30 days before being used for the first time in an official USA Fencing competition OR at the discretion of the head referee. Fencers must submit pictures that clearly show the entirety of the design. Accepted designs will be posted on the Fencing Officials Commission website."
Fencing blades come in 3 different lengths: Size 5 (35 inches long) is the standard size and used by everyone age ten and up. Children under 10 may use a Size 2 (32 inches long), or size 0 (30 inches long). While the size 0 blade is shorter, it is also lighter. This may make it more appropriate for some children.
Dry means non-electric, so a "dry mask" is a non-electric mask, and dry fencing is fencing without the electronic scoring machine.
The FIE is the international governing body. They have more restrictive regulations than USA Fencing. You do not have to meet FIE requirements to fence in USA fencing events. (Unless expressly stated so, such as the 800 N sabre glove)