I don't speak z, but does
delete the whole file, or just the member RMCST in file RMCST in library
A file member is like a partitioned table.
If you do a
QUOTE SITE DSPFD FILE(GDIDIVF/IIM) TYPE(*MBRLIST) OUTPUT(*PRINT)
Do you get an error that the file does not exist, or does the other system
generate a spool file listing the file but no member?