K,
It is not clear to me where within COMAC you are seeing these three phrases. Can you please elaborate?
If you are talking about the "Scope of processing", put your cursor on the field and press "F1" for detailed help on these choices.
You can see info about ATP check and about Material Checking group in online help at
Checking the Availability of Material - Production Orders (PP-SFC) - SAP Library
Best Regards,
DB49