Originally posted by norraba
under demon summoning there is the option to have the demon summoned work for you for a year and a day or for a specific task until its completion, is it possible to have as part of the specific task that the demon forget ever being summoned in the first place?
No, for two reasons. First, a specific task is a single task. The summoner definitely has scope to provide essential detail that is part and parcel of the task, but "and then do this unrelated other thing once you're done" clearly denotes a separate task. Second, demon binding magically enforces loyalty, but doesn't provide any other special means of affecting the bound demon's mind. Unless the demon explicitly has an applicable memory-erasing power, it can't forget things on command any better than a loyal mortal servant can.