The following should be placed atop the category page:
This category contains lists of professional American football teams that either played or were headquartered the city indicated by the list article's title. Teams qualifying for these list are those that competed in the National Football League, the various pre-1970 leagues named American Football League, the post-1945 leagues that competed against the NFL (including the World Football League, United States Football League, AAFC, and the Canadian Football League but not the XFL), and the highest level pre-1945 minor leagues. Teams that competed in the orginal Arena Football League (pre-2009) are included in the article.
The following guidelines for criteria should be included in the category talk page as there is no parent article for this category:
Cities worthy of this article must be major metropolitan cities, each having had at least three major professional football teams either based in the city or playing their home games in the city's metropolitan area.
The title of each article in the series shall be in the form similar to List of professional American football teams in Miami, which appropriate redirects at List of pro football teams in Miami, Miami professional football teams, Miami pro football teams, Professional American football teams in Miami, Pro football teams in Miami, etc. Articles for teams with only two such teams should be at a similar title, but omitting "List of" (this can be reserved as a redirect; no similar article should be created for cities (like Green Bay) that were served by only one professional American football team.
Categories for each article should be one pertaining to the city itself and the new Category:Lists of professional American football teams by city (which will be formed with the creation of the first article of this series); the parent category of this one is Category:American football teams by city.
See User:B.Wind/List of professional American football teams in (city)#Article format for a guideline on the format of the component articles.