Z80 /WAIT signal question

[Eric Smith]

A friend building a Z80 system asked me about whether the Z80 /WAIT
signal has any effect during machine cycles that aren't
memory/IO/intack cycles (i.e., neither /MREQ and /IORQ asserted). The
user manual only describes the use of /WAIT for adding wait states, so
I expect it probably only affects mem/IO/intack cycles, but I can't
find anything definitive in the user manual.

I'm hoping someone can save me the time of hooking up a logic analyzer
and running the experiment.

Thanks!
Eric