Most calls are made to a fixed address whose value is completely determined by the time the program starts execution. There are, however, certain cases that cause the exact address not to be determined until the code is actually executed. In this case, the procedure value representing the procedure to be called will be computed in a register.
Suppose R4 contains such a computed procedure value (simple or bound). An example of the code to call the procedure that it describes is:
JSR R26, (R4)