By the way, this word "chapter" is unfamiliar for me, a German. I did not hear it before I became a Wikimedian. What does this English word mean? Any sub division of an organisation, or is it rather associated to a city than to a country?
A chapter is a sub-division of an organisation. I'm not sure it's really the best word to describe our "chapters", since they are very much independent. They are more local affiliates than chapters.
The word "local" in German ("lokal") means: related to a city. What does it mean when English speaking Wikimedians talk about "local chapters"? Shouldn't it be "national chapters"? I consider Germany as a national, not a local entity...
"Local" in English just means related to a certain geographical area, the definition does not specify the size of that area. It is usually clear from context - it can refer to anything from a village to the Local Group, the collection of galaxies that the Milky Way is part of.