City of Pontiac Zoning Codes, Section 3.18 states the following:  Garages sales, retail sale parties and other similar functions held at a residence shall not constitute a home occupation and shall be permitted under this ordinance as incidental to a residential use, provided that said activity is not conducted for more than six (6) calendar days during any calendar year, which may be, but need not be, consecutive. 

Pontiac Zoning Code, Section 7.04 for General Standards for Signs, states the following:

1.  No sign shall be located in the vision clearance triange of a corner lot

2.  No sign shall be attached to a tree or utility pole, nor attached to public traffic signals.

It is the responsibility of the citizen to follow the regulations listed above and any person who placed the allowed "garage sale" signs through out the community must REMOVE said signs immediately after the sale.  Signs which are posted that do not follow the above regulations shall be removed.