Service Program
From MidrangeWiki
A service program is a collection of ILE modules that are bound into a single object of type *SRVPGM.
A service program itself is not executable, but it can be called by many other ILE programs to execute the routines contained within.
Service program objects have Signatures (that are similar to file format level identifiers, which are the source of Level Check errors) that are controlled by Binder Source.