Legal Question in Constitutional Law in Missouri

It's not an acronym. Licensed attorneys have been called "members of the bar" for centuries because, in British courtrooms of the time (and in most U.S. and British courtrooms even today), there was a bar of wood separating the rear area where anyone could sit from the front area reserved only for lawyers. The test which aspiring lawyers must pass is called the "bar exam" because only those who pass it may sit in front of the courtroom bar.

The language you quoted about "British Accredited Registry" is nonsense. It refers to an idea which the "Sovereign Citizen" movement teaches as if it were true. (For instance, its followers claim that courtrooms with gold-fringed American flags -- a strictly decorative choice -- are Maritime courts which have no jurisdiction over non-maritime cases.) That entire movement is based on gross misrepresentations of history and the law. Essentially everything it teaches is a lie. Don't let its adherents mislead you,