diff --git a/18.md b/18.md
index 41c9442..448171f 100644
--- a/18.md
+++ b/18.md
@@ -30,6 +30,11 @@ of the `mark` argument.
 
 `["q", <event-id>, <relay-url>, <pubkey>]`
 
+When quoting an event by address, `q` tags should follow conventions for `a` tags,
+as described in [NIP 01](./01.md).
+
+`["q", <event-address>, <relay-url>]`
+
 Quote reposts MUST include the [NIP-21](21.md) `nevent`, `note`, or `naddr` of the
 event in the content.