I've been thinking of something when you have an important move like
Toxic,Recover and you make a mistake of replacing all the moves with fly.
There should be an option on the move list to lock a certain move
and it cant get replaced by another move..

I like this idea because I was getting fly for the pokemonin my 2nd slot and my pokemon with toxic in the 1st slot had the moves replaced
instead of the one in the 2nd slot I had too buy another one again took a few weeks hope one of the Admins see this and think about adding it
:)

Fly does not replace Toxic or any other TM moves