IBM Professional Series User Manual page 290

Note: Output translation does not occur for SCRIPT
files when the SCRIPT command output is directed to
the terminal, nor when you use the CMS editor on a
display terminal in display mode.
ABBREV ON
accepts system and user abbreviations for system
commands. The SYNONYM command makes the system
and user abbreviations available.
ABBREV OFF
accepts only the full system command name or the full
user synonym (if one is available) for system commands.
For a discussion of the relationship of the SET ABBREV
and SYNONYM commands, refer to the SYNONYM
command description.
IMPEX ON
treats EXEC files as commands; an EXEC file is
invoked when the filename of the EXEC file is entered.
IMPEX OFF
does not consider EXEC files as commands. You must
issue the EXEC command to execute an EXEC file.
IMPCP ON
passes command names that CMS does not recognize to
CP; that is, unknown commands are considered to be CP
commands.
IMPCP OFF
generates an error message at the terminal if a command
is not recognized by CMS.
CMSTYPE HT
suppresses CMS terminal display within an EXEC. All
CMS terminal display from an EXEC, except for CMS
error messages with a suffix letter of'S' or 'T', is
suppressed until the end of the EXEC file or until a SET
CMSTYPE RT command is executed.
CMSTYPE RT
resumes CMS terminal display which has been
suppressed as a result of a previous SET CMSTYPE HT
command.
Chapter 7. VM/PC Commands
7 -117