- A message is called "excluded" if it matches at least one tag
- in search.tag_exclude that does not appear explicitly in the
- search terms. This option specifies whether to omit excluded
- messages in the search process.
+ A message is called "excluded" if it matches at least one
+ tag in search.tag_exclude that does not appear explicitly in
+ the search terms. This option specifies whether to omit
+ excluded messages in the search process.
+
+ The default value, <b>true</b>, prevents excluded messages from
+ matching the search terms.
+
+ <b>all</b> additionally prevents excluded messages from appearing
+ in displayed results, in effect behaving as though the
+ excluded messages do not exist.