The RexxDeregisterSubcom return values are:
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0 RXSUBCOM_OK A subcommand has executed
successfully.
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30 RXSUBCOM_NOTREG Registration was unsuccessful due to
duplicate handler and dynalink names
(RexxRegisterSubcomExe or
RexxRegisterSubcomDll); the
subroutine environment is not
registered (other REXX subcommand
functions).
──────────────────────────────────────────────────────────────────────
40 RXSUBCOM_NOCANDROP The subcommand handler has been
registered as "not droppable."
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