Section 232. Trade mark

If there is any quality mark printed, stamped or
  branded on the article itself there must also  be  printed,  stamped  or
  branded  on  the said article itself the following mark, to wit: a trade
  mark duly applied for or registered under the laws of the United  States
  of  the  manufacturer  of such article; except that if such manufacturer
  has sold or contracted to sell such article to a jobber,  wholesaler  or
  retail  dealer  regularly  engaged in the business of buying and selling
  similar articles, this provision shall be deemed to be complied with  if
  there  is  so  marked on the said article the trade mark duly registered
  under the laws of the United States of such jobber, wholesaler or retail
  dealer respectively; and in such event there may also be marked  on  the
  said article itself numerals intended to identify the article, design or
  pattern  provided,  however, that such numerals do not appear or purport
  to be a part of  the  quality  mark  and  provided  that  they  are  not
  calculated  to  mislead  or  deceive anyone into believing that they are
  partly of the quality mark.