# NIP-10

NIP-10 discusses the use of "e" and "p" tags in text events (kind 1), specifically in replies to other text events. It aims to help clients thread replies into a tree rooted at the original event.

Positional "e" tags (DEPRECATED): The positional "e" tags are now considered deprecated, but they were commonly used in the following ways:

* No "e" tag: The event is not a reply or reference to any other event.
* One "e" tag: The event is a reply to another event.
* Two "e" tags: The event is a reply to another event, with a root event id and a reply event id.
* Many "e" tags: The event contains a root event id, multiple mention event ids, and a reply event id.

Marked "e" tags (PREFERRED): The marked "e" tags are preferred because they allow events to mention others without confusing them with reply or root ids. Marked "e" tags have the following structure:

* \["e", \<event-id>, \<relay-url>, \<marker>]
* \<marker> can be "reply," "root," or "mention."

The "p" tag: The "p" tag is used in text events to record who is involved in a reply thread. When replying to a text event, the reply event's "p" tags should contain all the original event's "p" tags and the pubkey of the event being replied to.

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