(a)   No licensed active master plumber shall allow his name to be used by any other person, directly or indirectly, to obtain a plumbing permit.
   (b)   No licensed active master plumber shall employ any person to perform plumbing work of a journeyman plumber who is not properly licensed as a journeyman plumber or an inactive master plumber.
   (c)   Except as is otherwise provided by this chapter, no person within the City on or after June 30, 2002 shall act or hold himself out to be or undertake or perform any work as a plumbing contractor without first registering with the Health Commissioner in the manner specified in this chapter.