diff --git a/01.md b/01.md
index 9e25ca9b..5873eb63 100644
--- a/01.md
+++ b/01.md
@@ -75,7 +75,7 @@ The first element of the tag array is referred to as the tag _name_ or _key_ and
 
 This NIP defines 3 standard tags that can be used across all event kinds with the same meaning. They are as follows:
 
-- The `e` tag, used to refer to an event: `["e", <32-bytes lowercase hex of the id of another event>, <recommended relay URL, optional>]`
+- The `e` tag, used to refer to an event: `["e", <32-bytes lowercase hex of the id of another event>, <recommended relay URL, optional>, <32-bytes lowercase hex of the author's pubkey, optional>]`
 - The `p` tag, used to refer to another user: `["p", <32-bytes lowercase hex of a pubkey>, <recommended relay URL, optional>]`
 - The `a` tag, used to refer to an addressable or replaceable event
     - for an addressable event: `["a", <kind integer>:<32-bytes lowercase hex of a pubkey>:<d tag value>, <recommended relay URL, optional>]`