The DYNEXIT command displays information about MVS dynamic exits.
Some of the exits are:
These exits are related to subsystem SLS0.
What is the subsystem SLS0 ?
Release : 16.0
Component : SYSVIEW
SYSVIEW has an internal list of subsystems for which it registers exits, SLS0 is one of them. It then also registers for any subsystems explicitly defined in SMFPRMxx.
SLS0 is a StorageTek subsystem.
Even if you don't have that subsystem the presence of the exit won't cause any problems, it will just never be invoked.