Canadian Armed Forces
Only service dress is suitable for CAF members to wear on any occasion, barring "dirty work" or combat. With gloves, swords, and medals (No. 1 or 1A), it is suitable for ceremonial occasions and "dressed down" (No. 3 or lower), it is suitable for daily wear. Generally, after the elimination of base dress (although still defined for the Air Force uniform), operational dress is now the daily uniform worn by most members of the CF, unless service dress is prescribed (such as at the NDHQ, on parades, at public events, etc.). Approved parkas are authorized for winter wear in cold climates and a light casual jacket is also authorized for cooler days. The navy, most army, and some other units have, for very specific occasions, a ceremonial/regimental full dress, such as the naval "high-collar" white uniform, kilted Highland, Scottish, and Irish regiments, and the scarlet uniforms of the Royal Military Colleges.

Q: What is only worn for very specific occasions?
a ceremonial/regimental full dress