Section 52. Notice, how served; proceedings when violated not removed

Such
  notice  may  be  served  personally or by mail, and if by mail it may be
  addressed to such master plumber at the address registered by  him,  but
  the failure of a master plumber to register will relieve the official or
  board  who or which appoints the plumbing inspector from the requirement
  of giving notice of violation. Unless the violation  is  removed  within
  three days after the day of serving or mailing such notice, exclusive of
  the  day  of  serving  or  mailing,  the  official or board who or which
  appoints the plumbing inspector may proceed according to law.