Messing in the Canadian Armed Forces (CAF) generally follows the British model, from whom most traditions have descended.
Basic regulations regarding the establishment and administration of Messes is contained in the Queen's Regulations and Orders and the Canadian Forces Administrative Orders.
As in the British Forces, there are normally three Messes: the Officers' Mess (often called the Officers' Wardroom on Naval establishments), for commissioned officers and officer cadets; the Warrant Officers' and Sergeants' Mess (Navy: Chiefs' and Petty Officers' Mess), for senior non-commissioned officers and warrant officers; and the Junior Ranks Mess, for junior non-commissioned officers, privates, and seamen. Most bases and stations have three Messes (Officers', Warrant Officers' and Sergeants', and Junior Ranks'). Many of these establishments have lodger units (such as Air Squadrons, Army Regiments, etc) who also have their own Messes. All of Her Majesty's Canadian Ships (HMCS) have three Messes aboard; this extends to Naval Reserve Divisions and other Naval shore establishments which bear the title HMCS.
Headgear is not worn in Canadian Messes, except:
by personnel on duty, such as a Duty or Watch Officer, or the Military Police;
as permitted on special occasions, such as during costume parties, theme events, etc; or
by personnel for whom wearing headgear is mandatory (i.e. Religious reasons).
There are customs and traditions that may vary from Mess to Mess and it is your obligation to learn and understand those that apply to your Regimental/Unit Mess. For instance, in some Messes, the usual "penalty" (which may only be executed if the offender voluntarily submits) applied to personnel who neglect to remove their headdress is to buy a round of beverages for the members present, should they so wish to accept the offer. The area from the entrance to the cloakroom, however, is normally considered a "neutral zone", and exempt from the no-headgear policy. This prohibition is also extended to civilians, who are normally requested to remove their headdress upon entering; should they decline, they may be refused entry; they are not, however, subject to the "round for the house" rule. Other local customs can detail who can sit in which chairs in the Mess, how the members of the Mess are addressed within the confines of the Mess, etc…
All CAF personnel, Regular and Reserve, must belong to a Mess, and are termed ordinary members of their particular Mess. Although normally on Federal property, Messes comply with the legal drinking age laws of their province; for example, an 18-year-old soldier may legally consume alcohol in a Quebec Mess, but not in one in Ontario, where the legal age is 19. However, despite being underage, the soldier may not be prohibited entry into the Mess.
CAF personnel are normally welcome in any Mess of their appropriate rank group, regardless of element; thus a Regimental Sergeant-Major of an Infantry battalion is welcome in a Chiefs' and Petty Officers' Mess (inter-service rivalries notwithstanding). Personnel of a different rank (except as noted below) must ask for permission to enter; that may be granted by the President of the Mess Committee, his/her designate, or the senior member present.
These restrictions are normally waived on certain special occasions, when the Messes are "opened" to all personnel, regardless of rank. These occasions may include (and will be locally published by the Mess Committee):
New Year's Day, January 1, called a "Levee”;
Canada Day, July 1; and
Remembrance Day, November 11.
The Commanding Officer (CO) of the establishment or unit that owns the Mess is permitted access to all his/her Messes; thus a ship's captain has access to his/her vessel's Chiefs' and Petty Officers' Mess, the CO of a regiment may enter any of his/her regimental Messes, and the Base Commander of a Canadian Armed Forces Base is welcome in any of his/her base's Messes. In practice, COs rarely enter anything other than the Officers' Mess unless invited, as a point of etiquette. In addition, duty personnel — such as a Duty NCO or Officer of the Watch — or the Military Police have access to any and all Messes for the purposes of maintaining good order and discipline. Chaplains are usually welcomed in all Messes.
As in the UK, Canadian Messes are run by the Mess Committee, a group democratically elected by the members of the Mess. One exception is on warships, where the president of the Junior Ranks Mess is a Master Seaman appointed by the CO. The Committee members are generally the same as those of their British counterparts, with the addition of special representatives for such things as sports, housing, morale, etc. These positions are normally spelled out in the Mess Constitution.
Every Mess has a constitution, which sets out the bylaws, regulations, and guidelines for such things as conduct of Mess Meetings, associate memberships, dress regulations within the Mess, or booking of the Mess by civilian organizations. The constitution and any amendments are voted upon by the members of the Mess.