Communities on Lemmy follow the rules of the community, and the instance that hosts that community. So, this would need to follow the rules of !leftymemes@lemmy.dbzer0.com and dbzer0, the instance that left memes is hosted on.
There are also some instances that will ban you for your comments/posts in other communities, but that’s not common for most places that you would want to post anyway, or unless you post something very awful.
Communities on Lemmy follow the rules of the community, and the instance that hosts that community. So, this would need to follow the rules of !leftymemes@lemmy.dbzer0.com and dbzer0, the instance that left memes is hosted on.
Both of these can be found in the sidebar on the main page of the community, aka !leftymemes@lemmy.dbzer0.com.
There are also some instances that will ban you for your comments/posts in other communities, but that’s not common for most places that you would want to post anyway, or unless you post something very awful.