- 'empty Headers with no content.
- 'newsgroups Newsgroup identical to Gnus group.
- 'to-address To identical to To-address.
- 'to-list To identical to To-list.
- 'cc-list CC identical to To-list.
- 'followup-to Followup-to identical to Newsgroups.
- 'reply-to Reply-to identical to From.
- 'date Date less than four days old.
- 'long-to To and/or Cc longer than 1024 characters.
- 'many-to Multiple To and/or Cc."
+ `empty' Headers with no content.
+ `newsgroups' Newsgroup identical to Gnus group.
+ `to-address' To identical to To-address.
+ `to-list' To identical to To-list.
+ `cc-list' CC identical to To-list.
+ `followup-to' Followup-to identical to Newsgroups.
+ `reply-to' Reply-to identical to From.
+ `date' Date less than four days old.
+ `long-to' To and/or Cc longer than 1024 characters.
+ `many-to' Multiple To and/or Cc."