I believe this issue has come up a number of times on various DBs. It concerns me that there are no published guidelines on BK; well, I've had a long look before without finding any.
Anyone new to the site is not going to be aware of the results of previous discussions.
If it is true that using Engines is allowed as long as players state that that is what they are doing, and if some people have even developed their own, then there could actually be some interesting engine-only tournaments here.
Would anyone else appreciate some official guidelines?