Merge remote-tracking branch 'upstream/master' into draft-event

# Conflicts:
#	README.md

1 files changed, 3 insertions, 3 deletions

diff --git a/01.md b/01.md
index 905e45f..b51fdf0 100644
--- a/01.md
+++ b/01.md
@@ -56,7 +56,7 @@ To prevent implementation differences from creating a different event ID for the
 
 ### Tags
 
-Each tag is an array of strings of arbitrary size, with some conventions around them. Take a look at the example below:
+Each tag is an array of one or more strings, with some conventions around them. Take a look at the example below:
 
 ```jsonc
 {
@@ -81,13 +81,13 @@ This NIP defines 3 standard tags that can be used across all event kinds with th
     - for a parameterized replaceable event: `["a", <kind integer>:<32-bytes lowercase hex of a pubkey>:<d tag value>, <recommended relay URL, optional>]`
     - for a non-parameterized replaceable event: `["a", <kind integer>:<32-bytes lowercase hex of a pubkey>:, <recommended relay URL, optional>]`
 
-As a convention, all single-letter (only english alphabet letters: a-z, A-Z) key tags are expected to be indexed by relays, such that it is possible, for example, to query or subscribe to events that reference the event `"5c83da77af1dec6d7289834998ad7aafbd9e2191396d75ec3cc27f5a77226f36"` by using the `{"#e": "5c83da77af1dec6d7289834998ad7aafbd9e2191396d75ec3cc27f5a77226f36"}` filter.
+As a convention, all single-letter (only english alphabet letters: a-z, A-Z) key tags are expected to be indexed by relays, such that it is possible, for example, to query or subscribe to events that reference the event `"5c83da77af1dec6d7289834998ad7aafbd9e2191396d75ec3cc27f5a77226f36"` by using the `{"#e": ["5c83da77af1dec6d7289834998ad7aafbd9e2191396d75ec3cc27f5a77226f36"]}` filter.
 
 ### Kinds
 
 Kinds specify how clients should interpret the meaning of each event and the other fields of each event (e.g. an `"r"` tag may have a meaning in an event of kind 1 and an entirely different meaning in an event of kind 10002). Each NIP may define the meaning of a set of kinds that weren't defined elsewhere. This NIP defines two basic kinds:
 
-- `0`: **metadata**: the `content` is set to a stringified JSON object `{name: <username>, about: <string>, picture: <url, string>}` describing the user who created the event. A relay may delete older events once it gets a new one for the same pubkey.
+- `0`: **metadata**: the `content` is set to a stringified JSON object `{name: <username>, about: <string>, picture: <url, string>}` describing the user who created the event. [Extra metadata fields](24.md#kind-0) may be set. A relay may delete older events once it gets a new one for the same pubkey.
 - `1`: **text note**: the `content` is set to the **plaintext** content of a note (anything the user wants to say). Content that must be parsed, such as Markdown and HTML, should not be used. Clients should also not parse content as those.
 
 And also a convention for kind ranges that allow for easier experimentation and flexibility of relay implementation: