It's currently not clear what community category is for, as it has a default description, and is all over the place.
I'm not a native speaker, so feel free to check the description I provide, but after quick analysis of what people use community category for I suppose a description can look like this:
Topics about Rust user groups, blogs or community events.
It may be also worth considering removing a note about "meetups" from announcements, as currently both announcements and community tags are used for that purpose.