My personal policy is to tag everything even slightly NSFW as NSFW. That would include texts as well. To the other hand I mark images as Sensitive Content only when they are fully explicit... And now when I'm thinking about it I wonder if the final event looks any different or if NSFW tag is the same thing as selecting the Sensitive Content option. I need to check the relay.
Discussion
I did a test and there is difference between #NSFW tag and setting the post as Sensitive Content.
This is how it looks like in #Plebstr.
