Supplementary Order of Battle
In the Canadian Army, the Supplementary Order of Battle is a category of regiments that are reduced to zero strength but continues to exist administratively. This is done when the need for the regiment's continued operation is no longer relevant, and the regiment is re-manned only when the Department of National Defence deems the unit is required again. The Supplementary Order of Battle was instituted during the army rationalizations in the 1960s as an alternative to outright disbandment. If a regiment is re-manned and moved from the Supplementary Order of Battle, it takes its old place in the order of precedence and its colours, traditions and battle honours remain as if there had been no interruption of service.
In contrast, regiments that are completely disbanded are not placed on the Supplementary Order of Battle. For example, the Canadian Airborne Regiment was completely disbanded in the aftermath of the Somalia Affair in 1993, and is not placed on the Supplementary Order of Battle.
Three regiments have been removed from the Supplementary Order of Battle by amalgamating them with existing Primary Reserve units: the Irish Fusiliers of Canada (The Vancouver Regiment), on the order since 1965, was merged into the British Columbia Regiment (Duke of Connaught's Own) in 2002. The 19th Alberta Dragoons, also on the order since 1965, was merged into the South Alberta Light Horse in 2006. The Royal [Rifles of Canada], on the order since 1966, was merged into the Voltigeurs de Québec in 2019.
On September 5, 2008, Canadian Defence Minister Peter MacKay announced that The [Halifax Rifles (RCAC)] would be reorganized as an active unit. The Halifax Rifles are the first, and so far only, regiment to rejoin the Primary Reserve from the Supplementary Order of Battle.
Regiments on the Supplementary Order of Battle
[Royal Canadian Armoured Corps]
| Regiment | Formed | To SOB | Headquarters |
| 4th Princess Louise Dragoon Guards | 1875 | 1965 | Ottawa |
| 12th Manitoba Dragoons | 1903 | 1964 | Winnipeg |
| 14th Canadian Hussars | 1910 | 1968 | Swift Current |
[Royal Regiment of Canadian Artillery]
[Royal Canadian Infantry Corps]
| Regiment | Formed | To SOB | Headquarters |
| Canadian Guards | 1951 | 1970 | Petawawa |
| Victoria Rifles of Canada | 1862 | 1965 | Montreal |
| Régiment de Joliette | 1871 | 1964 | Joliette |
| Perth Regiment | 1886 | 1965 | Stratford, Ontario |
| South Saskatchewan Regiment | 1905 | 1968 | Estevan |
| Winnipeg Grenadiers | 1908 | 1965 | Winnipeg |
| 1st Battalion, Irish Regiment of Canada | 1915 | 1965 | Toronto |
| Yukon Regiment | 1962 | 1968 | Whitehorse, Yukon |