Specifications about #nip

Kind 2003, a torrent index carrying the info hash, the file list and the trackers needed to rebuild a magnet link.

Kind 27235, an ephemeral event signed to authorise a single HTTP request.

The content-warning tag, which asks a client to hide an event until the reader chooses to see it.

The subject tag, which gives a note a heading the way an email has one.

The old #[index] notation for mentioning events and pubkeys inside a note, replaced by NIP-27.