Thus `George-Washington-1776` is a valid `<username>`, but `George Washington` is not. Clients may reject metadata that does not comply.
- `1`: `text_note`: the `content` is set to the text content of a note (anything the user wants to say).
- `1`: `text_note`: the `content` is set to the text content of a note (anything the user wants to say). Non-plaintext notes should instead use kind 1000-10000 as described in [NIP-16](16.md).
- `2`: `recommend_server`: the `content` is set to the URL (e.g., `https://somerelay.com`) of a relay the event creator wants to recommend to its followers.
A relay may choose to treat different message kinds differently, and it may or may not choose to have a default way to handle kinds it doesn't know about.
Relays may decide to allow replaceable and/or ephemeral events.
Regular Events
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A *regular event* is defined as an event with a kind `1000 <= n < 10000`.
Upon a regular event being received, the relay SHOULD send it to all clients with a matching filter, and SHOULD store it. New events of the same kind do not affect previous events in any way.
Replaceable Events
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A *replaceable event* is defined as an event with a kind `10000 <= n < 20000`.