Stammtisch or regulars’ table in English is a common phenomena in German-speaking DACH countries (DACH stands for Deutschland (D), Austria (A) and Switzerland (CH), the 2 or 3 letters found on Euro auto license plates), where people meet informally and regulars usually at a local restaurant or pub.
While these are privately organized gatherings and not associated with Märklin company, Märklin/Trix lists where you can find them around the world.
Germany
- MIST 55, Mainz (Deutsch)
- MIST 61, Hochtaunus (no website, link to my Facebook album on their layout)

My home “club” Märklin Insider Stammtisch 61
- MIT Nord (Deutsch)
Austria
Malaysia
- Märklin Malaysia Fan Facebook Group (English)