Use {{location|RU}} to tag expeditions that took place in Russia. It will add Category:Meetup in Russia to the expedition.
Using ISO 3166-2 abbreviations, you may also tag the federal subject that the expedition took place in. Per ISO 3166, Crimea and Sevastopol are part of Ukraine, use {{location|UA}} to tag expeditions taking place there.
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 Moskva is a subcategory of Category:Meetup in Russia. The subcategories should be sorted in by their respective code.
Examples
{{location|RU}}: Russia{{location|RU|MOW}}: Moskva
