Use {{location|MX}} to tag expeditions that took place in Mexico. It will add Category:Meetup in Mexico to the expedition.
Using ISO 3166-2 or postal abbreviations, you may also tag the state that the expedition took place in.
If the category link appears red, do not worry and create the category. Make sure that it is included in the appropriate parent category, for instance, Category:Meetup in Puebla is a subcategory of Category:Meetup in Mexico. The subcategories should be sorted in by their respective code.
Examples
{{location|MX}}: Mexico{{location|MX|PUE}}: Puebla
