| Absorbed By |
Unit and its lineage is absorbed by another unit and its name ceases to be used |
| Inactivated |
Unit still formally exists on paper but has no men or equipment and can be reformed in the future |
| Amalgamated From |
Unit is created by the Amalgamation of other Units |
| Separated From |
Unit is separated from another unit which is divided into two new units |
| Broken Up |
Unit is broken up permanently (but not officially disbanded or inactivated) |
| Activated |
Unit is raised having previously existed on paper (US Only) |
| Also Known As |
Unit had another designation during the period indicated |
| Overrun |
Unit was dispersed through enemy action |
| Embodied |
Unit that was previously Inactive is staffed and equipped (equivalent to Mobilised) |
| Active |
Unit was in existence on this date and was already "mobilised" |
| Authorised |
Unit is authorised to be raised |
| Battle Honour |
Official Battle Honour awarded to this unit (British and US units only) |
| Created |
Unit is created or raised from scratch |
| Assimilated |
Unit is reinforced with the personnel of a disbanded Unit |
| Received Elements From |
Unit received elements from another unit which continued to exist |
| Contributed To |
Unit contributed elements to another unit and continued to exist |
| Disbanded |
Unit ceases to exist as a separate unit even on paper |
| Detached From |
Unit is detached from a parent unit |
| Demerged From |
Unit is split off from a unit into which it had been merged which continued to exist |
| Demerged |
Unit split off a previously merged unit and continued to exist |
| Disbanded Into |
Unit is disbanded and its personnel are transfered to another unit |
| Demobilised |
Unit Personnel are released from service |
| Detached |
Unit detachs sub-unit(s) |
| Disembodied |
Unit still exists on paper but has no men (equivalent to Suspended Animation) |
| Reformed |
Unit has previously existed and is recreated |
| Codenamed |
Alternative deception name is used by this unit on or after this date |
| Event |
An event in the history of the unit |
| Inactive |
Unit is in existence and has men assigned to it but is not "mobilised" on a specific date |
| Inducted |
National Guard unit is taken into Federal Service |
| Absorbed |
Unit absorbed another unit and lineage and retained the same name |
History Types are used to categorise the events in a Unit's life history such as Creation, Amalgamation, Disbandment, Reformation etc.