Sec. 13. Every holder of a certificate of registration as a registered architect shall display such certificate in a conspicuous place in his principal office, place of business or place of employment.
Every registered architect shall have a seal or design authorized by the board, the impression of which shall contain the name of the architect and the words, "registered architect", "state of Indiana". He shall stamp with this seal all working drawings, reports, and specifications prepared by him or under his supervision.