Thanks ChristiaanJ
Yeah, I'm just trying to find out if someone has a definition of what Mdi (or it may have been Mde) is that was being referenced. The rest of my first post was explaining the context of the situation when it came up. I was talking to a senior airbus guy who I believe was of British background.
I'm just looking for the definitions (or a reference of different M speeds) for my own interest.
Thanks