|My understanding is you have 10 buddy passes per year.
You also have a limit of 8 zed fares (for buddies) on Star Alliance partners per year. (Non-star alliance zed fares are not available for buddies, only for your parents and dependent children under 25 years who are actively pursuing education and don't have a full time job)
You buddy pass means a round trip that starts and ends from the same destination and is completed (I believe) within 90 days or less.
For example YYZ - FRA - YYZ
YYZ - CDG (leg 1)
FRA - YUL (leg 2)
YUL - YYZ (leg 3)
Hope that helps and always double check with your profile or employee travel helpdesk before your trip. Don't take my word for it