Be wary of formal fine-grained content 'classification' proposals for Nostr that claim to help individual communities or specific groups (sexuality, children, religion); as they are effectively future backdoor censorship for all content - even if well intentioned today.
If your community or group needs to opt-into a 'self-isolation bubble' for whatever reason, that's a perfect use case for community run private relays. You can even moderate, and censor your community with your own rules, and even have special punishments - it just doesn't belong in a protocol designed to prevent censorship and arbitrary moderators making decisions on behalf of others.
