clarify composition a little more

docs/honk.5

@@ -58,7 +58,11 @@ or
 .Dq https
 will be autolinked.
 .El
-.Ss EXTRAS
+.Pp
+If the first line of a honk begins with
+.Dq DZ:
+(danger zone) it will be used a summary and the post marked sensitive. 
+.Pp
 Mentioning a specfic user such as
 .Pq @user@example.social
 will send a copy of the message to them.
@@ -72,7 +76,7 @@ will work for anyone.
 .Ql @https://example.com
 works as well.
 When honking back, the author of the parent post is automatically mentioned.
-.Pp
+.Ss EXTRAS
 Threads from the tiny bird site may be included as quotes in a post via the
 .Ar hoot
 operator followed by the URL.