@aetataureate You make a very good point about the dubious value of putting age ratings on social media content, but having re-read your OP when less tired, I wonder if we're perhaps talking at cross purposes? (Or if I was, at least.)
One of the servers I run is small and free, but hosts more or less exclusively pornographic content. Its descriptions and the account descriptions on it indicate this, and while legislation is about as a clear as mud even/especially in the wake of the DSA, I also don't see any reason NOT to accurately describe the content.
Although I feel that youth should have access to sex education materials and, based on having been a teenager, know for a fact that they will access porn when they want it, I equally make content that's sufficiently unsafe-for-anyone that I really don't want anyone, of any age, wandering into it unaware.
Do the age checks stipulated in SREN apply to me as a non-commercial entity, an individual? Who knows?!? Legislation literally does not say!
However, it seems that, as a bare minimum, correctly flagging the material I make as illegal for minors to access is at least wise.
But re-reading you now, I wonder: are you thinking perhaps more of legislation banning, say under-15s from social media in general?
Or blanket "minors DNI" stuff? (This comes off... awkwardly, but similarly usually strikes me more as queer, SW, and other minoritised sexual accounts playing it safe in terms of not being accused of "grooming", which unfortunately can and has happened.)
GNU social JP is a social network, courtesy of GNU social JP管理人. It runs on GNU social, version 2.0.2-dev, available under the GNU Affero General Public License.
All GNU social JP content and data are available under the Creative Commons Attribution 3.0 license.