What is an appropriate way to call another station on a repeater if you know the other station's call sign?
Why On a repeater, calling is conversational: you say the call sign of the station you want, then give your own call sign so everyone (and the FCC's identification rule, 97.119) knows who is transmitting. That is all it takes, since repeater users are usually monitoring and the machine covers the whole area. Example: "W1ABC, this is K2XYZ."
Watch out Saying "break, break" is reserved for interrupting a conversation with urgent or emergency traffic, so using it for a routine call is poor practice. Calling CQ is an HF and weak-signal simplex habit and is generally not used on FM repeaters, where you simply announce the call sign you want.
Repeater call = "their call, your call." Save "break" for emergencies and "CQ" for HF.