Cursing is when you use edgy filler words instead of saying something meaningful.

Swear words are fine. Attacking people's weight (or age, sexuality, gender, etc) should be avoided.

I'll admit that there is gray area in this rule. On Lemmy there are many instances of posts mocking celebrities for different characteristics but the posts seem to be permitted if the celebrities are largely disliked.

I'll see if I can add a NSFW tag....