The terms Mainstream and Plus designate sets of named instructions that are called during the dance, with which the dancers are expected to be familiar. These same sets of calls (referred to as “dance programs” by Callerlab, (Click Link) which maintains the lists) are used throughout the square-dancing world. To dance at the Mainstream level, dancers must know all the calls from the Basic and Mainstream lists; to dance at the Plus level, dancers must know all calls from the Basic, Mainstream, and Plus lists. The lists of calls and their definitions are at http://www.callerlab.org/Dance-Programs.