diff --git a/18.md b/18.md
index 27c5915..3c6ca91 100644
--- a/18.md
+++ b/18.md
@@ -9,7 +9,7 @@ Reposts
 A repost is a `kind 6` event that is used to signal to followers
 that a `kind 1` text note is worth reading.
 
-The `content` of a repost event is _the stringified JSON of the reposted note_. It MAY also be empty, but that is not recommended.
+For security reasons, The `content` of a repost event MUST not be set _the stringified JSON of the reposted note_. It SHOULD also be empty.
 
 The repost event MUST include an `e` tag with the `id` of the note that is
 being reposted. That tag MUST include a relay URL as its third entry