+.BR \-\-exclude=(true|false|flag)
+
+Specify whether to omit messages matching search.tag_exclude from the
+search results (the default) or not. The extra option
+.B flag
+only has an effect when
+.B --output=summary
+In this case all matching threads are returned but the "match count"
+is the number of matching non-excluded messages in the thread.