Common.ai QUESTION

I find some native functions as follows:
DebugS
DebugFI
DebugUnitID
DisplayText
DisplayTextI
DisplayTextII
DisplayTextIII
DoAiScriptDebug

how to use them,and do what?

I would REALLY APPRECIATE if you answered the question.

Those natives did not seem to do anything visible when I tried them out back then.
I suspect they are only active if you run the game in a special debug mode.

@AIAndy:Thank you, I'll try it.