According to
Wikipedia there were 18 official sports categories at the 1968 Mexico City Games,
plus two Demonstration Sports (Basque pelota and Tennis).
Each sport area was assigned a pictogram - plus one for Water Polo (a subcategory of Aquatics, but whatever).
The images were used on tickets, street signs, maps, etc. to help guide foreign visitors to sports venues.
In addition, there was a logo to designate Information kiosks, shown below.
