The Canadian position (federal):

1) Employees of the Treasury Board (most public servants) are prohibited from collecting frequent flyer miles for official travel. This includes personal travel paid for by the Crown (such as home leave under the Foreign Service Directives).

2) Appointees of the Governor-in-Council and Members of Parliament are not employees of the Treasury Board, and are not covered by TBS travel policy.

M.P.'s and Senators are required, by Parliamentary rules, to accumulate and use frequent flyer miles for official travel.
Members of the RCMP and the Canadian Forces are covered by the travel policies of each of those forces.

Judges, tribunal members, and other GIC appointees are governed by the rules of the agency to which they are appointed.

3) F travel is strictly prohibited, except for diplomatic couriers, or as expressly authorized by a Minister. Ministers are accountable for these authorizations. Ministers may not authorize their own F class travel.

The Prime Minister and the Governor-General do not fly commercially, for security reasons.

4) J class travel can be authorized for all segments over 9 hours, all direct flights without deplaning over 12 hours, and all travel in excess of 14 hours in one day. J class will be authorized for the entire routing if there is no incremental cost (i.e. on YOW - YVR - HKG).

5) J class travel is not authorized if the employee travels via a circuitous routing (e.g. any routing other than the approved routing), even if there is no incremental cost. So you get J class for YOW-YVR-HKG, but you only get Y class for YOW-LAX-HKG.

6) Theoretically, J class may be authorized for members of the DM group (deputy ministers), the EX group (management), and professional groups which parallel the EX bands (eg, the LA-2B's and higher) for travel over 90 minutes. However, this policy has been under suspension for a very long time, now.