ACCEPT "identifier" detects mouse key sbut ACCEPT OMITTED does not detect mouse keys.
It may instead be necessary to detect the mouse keys when the program stops with accept omitted and waits for a user action.
see also:
https://sourceforge.net/p/open-cobol/discussion/cobol/thread/9f2e846cbe/#c608/0545
See also is now:
https://sourceforge.net/p/gnucobol/discussion/cobol/thread/9f2e846cbe/#c608/0545