Series consists of textual records outlining the general criteria used by Gordon Couling for his architectural inventory of buildings built in Guelph prior to 1927. Couling's criteria consisted of five different sets of priorities numbered one through five each accompanied by brief explanations for its use. Based on his criteria a building was then given a priority number. In addition, Couling sometimes included additional notes about a particular building's history and architectural features.
Couling's general criteria is explained at the beginning of the series followed by the priority sheets which are arranged alphabetically by street name.