The text defines a new kind of report called "report" that can be used to report other notes for spam, illegal or explicit content. The report event must include a p tag referencing the user you are reporting and an e tag referencing the note id if reporting a note. A report type string must be included as the 3rd entry to the e or p tag being reported, which consists of the following report types: nudity, profanity, illegal, spam, impersonation. Some report tags only make sense for profile reports, such as impersonation. L and L tags may also be used as defined in NIP-32(32.md).

Link: https://github.com/nostr-protocol/nips/blob/master/56.md