First I think I was trying to discern if a community is one even if it doesn't have salient language features such as a particular slang, recurrently-used phrases, and idioms or somethinkg the like. And I came to the conclusion that of course there are communities which may not share discrete language-related features but have common goals or situations that draw them close; for example, I live in a block of flats, and though whenever we communicate with my neighbours we don't necessarily make use of discourse-exclusive language, we do make reference to things which are only relevant to us as homeowners in the same building, so someone from the outside would never find any interest in those interchanges, and if new neighbours came to live here they would have to, peripherally, adapt day by day to the "buildingese", our mutually-accepted set of things we talk about.
Surely, I also found examples in my own life of communities which could easily be considered to have exclusive discourse characteristics: I'm a Muslim, and with my Muslim brothers or sisters we share a common religion-related language not only in Spanish, but also, and more importantly, in Arabic. So we talk about principles of the faith using Arabic terminology and may or may not find a need to translate it into our mother tongue. This is an example where the principles of belonging and periphery I mentioned above are immensely relevant, since when there's a new Muslim who embraces the religion they would always have to learn certain words or even phrases that are crucial to the practice of Islam, although they don't need to do so urgently and can absolutely take their time to learn. Nevertheless, this example shows that belonging to a community is something which, in many cases, is built brick by brick and may require more or less time to be accomplished.
I've got similar cases I could narrate here, for example the tech and gaming communities, to which I'm not sure I belong, but do certainly contribute to with posts and comments in various social media platforms. There, too, there are language features which are exclusive to each group and which may seem strange or just incomprehensible to an outsider.
Anyway, that's something I've been thinking about recently, thanks for reading!
