Can anyone tell me what MA and LA means at the top left of music frames in engrave mode?


I am pretty sure MA = Master and LA = Layout.

M = this frame comes from the master page, and L = this frame comes from a page in the layout, but the second letter is the identifier for the chain of frames itself, so the first one is indeed A, but if you create a new music frame you’ll see it has a different letter, normally H (since the other text frames in the master page are also numbered using the same scheme, though you can’t see their identifiers since they can’t yet be linked together).