As a Master Carpenter myself, it’s (1) analogous to a Master Electrician or Plumber, which is an actual requirement in many US States to even be able to pull (mechanical trade relevant) Permits, and/or to get a business license in said Trade. (2) A Master Carpenter would be at a Journey level or higher at anything carpenter related: Framing & Trim; Cabinetry & Furniture; Dock & Marine; Residential, Commercial or Industrial. It took me 2 decades to achieve this (74–96). Then Journey level as residential electrician (96–00). Was a Union and a non-union carpenter; a General Contractor too.