Call site

In programming, a call site of a function or subroutine is the location (line of code) where the function is called (or may be called, through dynamic dispatch). A call site is where zero or more arguments are passed to the function, and zero or more return values are received.

Assembler example
IBM/360 or Z/Architecture In some occasions, return is an efficient method of indicating success or failure. return may be accomplished by returning at +0 or +4,+8, +12, etc. requiring code, for example a small branch table, at the return point - to go directly to process the case (as in HLL Switch statement). Conventionally however, a return code is set in  ( =OK,  = failure, or similar ..) but requiring a separate instruction to test   or use directly as a branch index.