-that sequence. Hence, \*(lqnotseen\*(rq means all those messages that
-are not a member of the sequence \*(lqseen\*(rq. Read the
+that sequence. Hence, \*(lq!foo\*(rq means all those messages that
+are not a member of the sequence \*(lqfoo\*(rq.
+To deactivate this mechanism, define Sequence\-Negation to an empty value.
+Read the