Like BALR 14,15 (the 24-bit-only form of a call), BASSM is used as BASSM 14,15, where the linkage address and mode are saved in register 14, and a branch is taken to the subroutine address and mode specified in register 15. Somewhat similarly to BCR 15,14 (the 24-bit-only form of an unconditional return), BSM is used as BSM 0,14, where 0 indicates that the current mode is not saved (the program is leaving the subroutine, anyway), and a return to the caller at the address and mode specified in register 14 is to be taken. Refer to IBM publication MVS/Extended Architecture System Programming Library: 31-Bit Addressing, GC28-1158-1, for extensive examples of the use of BAS, BASR, BASSM and BSM, in particular, pp. 29–30.