Squire

Squire is a rank used in some of the splinter factions of the Brotherhood of Steel.

Fallout 3
The only Capital Wasteland Brotherhood of Steel member of this rank in 2277 is Arthur Maxson, which would imply that the rank is reserved for children and is lower than Initiate. It is possible that this rank is used similarly in the original Lost Hills Brotherhood.

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Fallout Tactics
In the Midwestern Brotherhood of Steel, Squires are one step above Initiates and are the least experienced and trained of the Brotherhood active military. Initiates are members who have completed initial training and the lowest rank that can be assigned to combat duty. Initiates are not, typically, allowed on the battlefield and instead are used where their skills are best served: KP duty. Squires are equipped with Leather armor.