Question: do I have to tag a post as NSFW if I am posting in an NSFW community?

Like, if I don't tag a post as NSFW does it still show up for people who don't want to see NSFW? Again, I'm only asking if this is necessary in NSFW communities. I know that I have to tag NSFW content in regular communities. But if I post in a community marked NSFW does it automatically mark the post as such or do I have to manually do it? I've got blur NSFW content turned on and it seems to be blurring the stuff in the community for me, but I wanna be certain that it's doing it everywhere that content is available like feeds and stuff.