Flying ARN-BRU-YUL-YYC on Monday. A post by [MENTION=168021]YVRtoYYZ[/MENTION] in the other OSS thread on the Canada forum suggests it's possible to get OSS on an itinerary like that with another carrier on the first leg, but in practice, anything special needed to achieve it? i.e. if I get BPs from SK, will they have ITD OSS on them for the connection at YUL? Or would I need to get new BPs from AC, either at BRU or via OLCI?

AC app says I won't need to clear security in YUL, but we all know how reliable it is.