Yes, sorry for my slightly crass reply but no-one can remember them unless they use them frequently. I asked a very experienced RAF ATCO the other day and he um'd and err'd for a while and said he'd get back to me since he never used them (well he does but it's just a red light or verey for don't land/go-around and a green light or verey for land).
Like a lot of the stuff we have to learn nowadays, memorise it for the exam then dump it
.