Galdian: apologies. I confused myself. Indeed, as you say. Deep in my memory, and playing hide & seek, is an item from B757/767 days where there was the ARM function in daily use. (I stand to be corrected). The reason I think I remember this is when I transferred companies onto B733 there were other B757 pilots who experimented with the 'hidden' ARM function and found it seemed to work. In that embryonic airline they discussed its use within the training dept only to be rebuffed as a no no. It was taken as a case of the people being spoken to were less experienced that those speaking and didn't understand the question. So the Ops guys went to Boeing and received the standard Boeing 'not recommended' and thus it became a DO NOT. On the outside it seemed the B757 AFDS was the same as B733, but we all know there are gremlins lurking behind the facia deep in the electronic bowls of the E&E bay. What seemed to be happening in Seattle was that the B737 fleet development dept operated separately to the very similar looking B757 dept. They introduced some similarities, perhaps in the hope of common type ratings, but not everything. (who ever thought that using the flap lever to drive the speed bug on GA was good idea. Duh!) I still think B737 ARM is a grey area. It might well work and work well, but I wonder if there are certification problems that are better left unopened? As a result, 'not recommended' is interpreted as 'not allowed' by the many, but not all. If some XAA's approve it what argument do those who deny it use?