(?:/(?:[A-Z]{1,2}\d+ | \d[A-Z]{1,2}\d+))? # / another prefix possibly
(?:/[0-9A-Z]{1,2})? # /0-9A-Z+ possibly
(?:-\d{1,2})? # - nn possibly
(?:/(?:[A-Z]{1,2}\d+ | \d[A-Z]{1,2}\d+))? # / another prefix possibly
(?:/[0-9A-Z]{1,2})? # /0-9A-Z+ possibly
(?:-\d{1,2})? # - nn possibly