If no operating system library can be determined, macros are stored in the SMPMTS library and the source in the SMPSTS library.

Macro and source elements stored in the SMPMTS or SMPSTS remain there until they are replaced by elements from subsequent APPLY processing or until the SYSMODs that modified them are applied. In this way, the SMPMTS serves as a macro library for assemblies during APPLY processing and must be in the concatenation of the SYSLIB DD statement for APPLY. Likewise, the SMPSTS serves as a source library for assemblies during APPLY processing, but is not required in the SYSLIB concatenation.