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+NIP-22
+======
+
+Comment
+-------
+
+`draft` `optional`
+
+A comment is meant to be used to comment on
+or reply to anything except [NIP-01](01.md) `kind:1` events
+and other event kinds whose specifications have already defined other
+ways to comment on or reply to them.
+
+For example, it can be used to comment on a [NIP-23](23.md) `kind:30023` nostr blog post
+or on an off-nostr news article or to reply to another comment.
+
+## Structure
+
+A comment is an event of `kind:1111` with plaintext `.content`
+(no HTML, no Markdown nor other formatting).
+
+It must have a `k` tag pointing to the kind of the subject being commented on.
+For example, when commenting on a `kind:30023`, the `k` tag is set to "30023".
+When replying to another `kind:1111`, the `k` tag is set to "1111".
+If commenting on an `https://abc.com/articles/1` artcile the `k` tag is set to "https://abc.com" (its domain).
+
+### Threads
+
+There is always an `o` tag pointing to the original post that started the thread.
+It can be an event id (with an "i:<event-pubkey>:" prefix),
+an event address ("a:" prefix) or an url ("<protocol>" prefix). The second value
+is the optional recommended relay url where the referenced event may be found.
+This tag is useful to load all messages of a thread at once.
+
+Note that if commenting on a replaceable event, one can choose to add both id and address references.
+
+Examples:
+
+- `["o", "i:<event-pubkey>:<event-id>", "<relay-url, optional>"]`
+- `["o", "a:<event-address>", "<relay-url, optional>"]`
+- `["o", "https://abc.com/articles/1/"]`
+
+Also, there is always an `r` tag pointing to the subject being directly commented on or replied to, using the
+same structure of the `o` tag.
+This tag is useful to lazily load a thread.
+
+### Event Examples
+
+```js
+{
+  kind: 1111,
+  content: 'Agree with your comment.',
+  tags: [
+    // referencing the OP
+    ["o", "https://abc.com/articles/1/"],
+    // replying to a parent kind:1111 comment
+    ["r", "i:f7234bd4c1394dda46d09f35bd384dd30cc552ad5541990f98844fb06676e9ca:5c83da77af1dec6d7289834998ad7aafbd9e2191396d75ec3cc27f5a77226f36"],
+    // the parent kind
+    ["k", "1111"]
+  ]
+  // other fields
+}
+```
+
+```js
+{
+  kind: 1111,
+  content: 'Great blog post! Check this out nostr:npub1sn0wdenkukak0d9dfczzeacvhkrgz92ak56egt7vdgzn8pv2wfqqhrjdv9.',
+  tags: [
+    // top-level comments have the same o and r tags
+    ["o", "a:30023:3c9849383bdea883b0bd16fece1ed36d37e37cdde3ce43b17ea4e9192ec11289:f9347ca7"],
+    ["r", "a:30023:3c9849383bdea883b0bd16fece1ed36d37e37cdde3ce43b17ea4e9192ec11289:f9347ca7"],
+    // the parent kind
+    ["k", "30023"],
+    // the nostr:npub1... mentioned on .content
+    ["p", "84dee6e676e5bb67b4ad4e042cf70cbd8681155db535942fcc6a0533858a7240"]
+  ]
+  // other fields
+}
+```
+
+Note that ideally there are no `p` tags unless the pubkey is being mentioned on the `.content`.