Causes the debugger to break on the return instruction of the
    routine associated with the specified address expression (which
    can be a routine name, line number, and so on). Breaking on the
    return instruction enables you to inspect the local environment
    (for example, obtain the values of local variables) while
    the routine is still active. Note that the view of a local
    environment may differ depending on your architecture. On Alpha
    processors, this qualifier can be applied to any routine.

    The address-expression parameter is an instruction address within
    a routine. It can simply be a routine name, in which case it
    specifies the routine start address. However, you can also
    specify another location in a routine, so you can see only those
    returns that are taken after a certain code path is followed.

    A SET TRACE/RETURN command cancels a previous SET TRACE if you
    specify the same address expression.