View Source Nostr.Event.Types.RepostEvent (Nostr v0.1.3)
Repost event management, including event creation and parsing
Note that this kind of event has been officially removed by fiatjaf from the official specification, so kind 6 doesn't exist anymore at the moment of this writing. Clients are still using it so it will remain by the time being.
As a reference, here's a link to the NIP before it's been deleted: https://github.com/nostr-protocol/nips/blob/e5ae318984bdc2f28932420be976183c9a0cd3ff/18.md