Very straightforward. You may notice that there are 2 sequences of flight numbers on the BE timetable (I don't see types listed on their online tinetable): those beginning BE31 and those beginning BE74 (that's when you ignore the current block beginning BE72 which end with the summer timetable). If BE is operating all, you would expect them all to be sequential.
Then read OltonPete's post in reply 390 in this thread which is based on the AF website and states that there's 3 AF services. Look at the times that's been quoted for BE operations and it's clearly demonstrated that the BE31 series are those for the Q400 and Emb195 and the ones beginning BE74 are the BE codeshares for the AF services.