nips/10.md

NIP-10

On e and p tags in Text Events (kind 1).

draft optional author:unclebobmartin

A Conventional use of e and p tags within clients.

The following seems to be the conventions that are used by Branle, Damus, and more-speech for referencing events and authors when building a reply. These conventions help clients build event threads, and alert authors of replies.

Definitions:

• A reply chain is the list of events from the root event to a specific reply.
• A reply thread is the tree of events consisting of all replies beginning at the root.
• An event id is a 32 byte number in lower-case hexidecimal.

The e tag

Used in a text event contains a single event id. ["e", "hex-number"]

• No e tag: This event is not a reply to, nor does it refer to, any other event.

• One e tag: ["e",id]: The id of the event to which this event is a reply.

• Two e tags: ["e",root-id], ["e",reply-id] 'root-id' is the id of the event at the root of the reply chain. reply-id is the id of the article to which this event is a reply.

• Many e tags: ["e",root-id] ["e",mention-id], ..., ["e",reply-id] There may be any number of mention-ids. These are the ids of events which may, or may not be in the reply chain.
  They are citings from this event. root-id and reply-id are as above.

The p tag

Used in a text event contains a list of pubkeys used to record who is involved in a reply thread.

When replying to a text event E with p tags P, the replying event's p tags should contain P as well as the pubkey of the of the event being replied to.

Example: Given a text event authored by a1 with p tags [p1, p2, p3] then the p tags of the reply should be [a1, p1, p2, p3] in no particular order.