* document the new flag:list

man/mu-find.1

@@ -137,6 +137,7 @@ of the message, as listed in the following table:
 	a,attach        Has attachment
 	z,signed        Signed message
 	x,encrypted     Encrypted message
+	l,list          Mailing-list message
 .fi
 
 Using this, we can search e.g. for all signed messages that have an

mu4e/mu4e.texi

@@ -1602,6 +1602,11 @@ wildcard can only appear as the term's rightmost character:
 subject:soc*
 @end verbatim
 
+@item Get all messages @emph{not} sent to a mailing-list:
+@verbatim
+NOT flag:list
+@end verbatim
+
 @item Get all mails with attachments with filenames starting with @emph{pic}; note
 that the '*' wildcard can only appear as the term's rightmost character:
 @verbatim