diff --git a/71.md b/71.md
index 6d6775a4..0a60d61f 100644
--- a/71.md
+++ b/71.md
@@ -39,6 +39,7 @@ The list of tags are as follows:
 * `image` (optional) url of preview image with same dimensions
 * `content-warning` (optional) warning about content of NSFW video
 * `alt` (optional) description for accessibility
+* `segment` (optional, repeated) start timestamp in format `HH:MM:SS.sss`, end timestamp in format `HH:MM:SS.sss`, chapter/segment title, chapter thumbnail-url
 * `t` (optional, repeated) hashtag to categorize video
 * `p` (optional, repeated) 32-bytes hex pubkey of a participant in the video, optional recommended relay URL
 * `r` (optional, repeated) references / links to web pages
@@ -71,6 +72,7 @@ The list of tags are as follows:
     ["i",<torrent infohash>],
     ["text-track", "<encoded `kind 6000` event>", "<recommended relay urls>"],
     ["content-warning", "<reason>"],
+    ["segment", <start>, <end>, "<title>", "<thumbnail URL>"],
 
     // Participants
     ["p", "<32-bytes hex of a pubkey>", "<optional recommended relay URL>"],