Use {{location|TR}} to tag expeditions that took place in Turkey. It will add Category:Meetup in Turkey to the expedition.
Using ISO 3166-2 abbreviations, you may also tag the il that the expedition took place in. Sometimes an il consists of one city only, in which case the word ili is obsolete.
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 İstanbul is a subcategory of Category:Meetup in Turkey. The subcategories should be sorted in by their respective code.
Examples
{{location|TR}}: Turkey{{location|TR|34}}: İstanbul{{location|TR|81}}: Düzce ili
