Allow instances to mark themselves as NSFW

[3pleunderscore]

Requirements

• Is this a feature request? For questions or discussions use https://lemmy.ml/c/lemmy_support
• Did you check to see if this issue already exists?
• Is this only a feature request? Do not put multiple feature requests in one issue.
• Is this a backend issue? Use the lemmy-ui repo for UI / frontend issues.

Is your proposal related to a problem?

This is an attempt to solve both discoverability and usability of NSFW communities built on Lemmy, especially for logged-out visitors.

Describe the solution you'd like.

Introduce an "Is NSFW Instance" option with three states:

• No, which will be the state of things as is right now
• Partial, which is intended for instances that are not NSFW focused, yet allow it. This setting will
  • List NSFW communities to logged out people, potentially with blurred icons and banners
  • Show NSFW posts on NSFW communities to logged out people by default, with blurred thumbnails
    • NSFW posts will still be hidden on public timelines or communities marked as SFW without being logged in
• Yes, which is intended for instances that are explicitly focused on NSFW content. This setting will expand upon Partial by
  • Marking all new communities and posts in them NSFW by default (and those that are not will still be able to un-check the box)
  • Displaying NSFW content everywhere, without any blurring
  • Displaying an interstitial to the tune of "This site is focused on adult content, only enter if you are +18 and if it's legal for you to do so" on first visit

A setting like this could also form the basis of any kind of NSFW-specific (de)federation options, though I am not exactly sure where on the ActivityPub spec we'd throw that information in.

Describe alternatives you've considered.

There are several issues and PRs made about individual users' choices on how they wish to see NSFW content, but I haven't seen any concerning logged out visitors.

Additional context

I may be able to do the programming if upstream is OK with having this in.

If this shows up as a duplicate it's because GitHub seems to have shadowbanned my previous account. So here is a less throwaway-y one.

[dropdevrahul]

@3pleunderscore if this gets approved let me know if you need any help

[airjer]

Would love to see this implemented.

[Nutomic]

#4393