A historical reenactor (especially a US civil war reenactor) whoever attempts at a historically precise portrayal tend to be, inside opinion for the presenter, insufficient. (for instance, using today's wristwatch with period costume.) The alternative of farb is "hard-core" (or hardcore), someone who is, in the opinion of the presenter, an "authenticity fanatic".
Definition for "farb"
A historical reenactor (especially a US civil war…