In addition to the switches 0 to 8 supported by COBOL, another form of switch-name can be used. It is an upper-case letter in the range A to Z.
These letters are mapped to switches 0 to 25, so at run time you should use the appropriate digit on your command line and not the letter itself.
For example, to turn on switch J you would put:
+9 filename
after the run command. You cannot, however, specify a run-time switch in a CALL statement, as in:
CALL "PROG.INT/A"
because this is not supported.