Problem:

Is it possible to skip lines of COBOL source code at run-time and activate them when necessary, for instance during a debugging session?

Resolution:

Starting from release 8.1, ACUCOBOL-GT introduced a way to comment source lines out.
These can be activated only when necessary.

To use this new functionality, mark these lines with a "D" in the indicator area at column 7 (or with a "\\D" in terminal format).
i.e.:

       MAIN-LOGIC.

            MOVE "Begin Program" to ws-text 
            display message box ws-text 

      D     MOVE "Debug this" to ws-text 
      D     display message box ws-text

            MOVE "End Program" to ws-text 
            display message box ws-text

            goback.

By default, the lines marked with "D" will be considered as commented and will be ignored by the runtime.

To activate these lines, compile the program adding the flag -Sd.

From the ACUCOBOL-GT Version 10.0 Documentation Set > ACUCOBOL-GT User's Guide > Compiler and Runtime > Using the Compiler
Source Options

Setting this -Sd option causes debugging lines marked with D in the indicator area to be treated as normal source lines instead of comment lines.
This is equivalent to supplying the phrase WITH DEBUGGING MODE in the SOURCE-COMPUTER paragraph.