DSC PC1555 PGM outputs

Hi everyone.
I?m new with alarm systems, I?m working with a PC1555 of DSC and rn I?m focused on working on pgm outputs, so I have this question:
How does the 21 y 22 options work? They just say ?For future use? so I?m not sure how do they work.
I put the pgm outputs as 21 while connected to a 120V lamp, which works perfectly with other pgm options, as 06 (ready to arm), 07 (keypad buzzer follower mode) etc. But with 21 and 22 options nothing happened.
Any comments will be well received. Have a great day! :slight_smile: