Allow Dictionaries with "Subject only" Compliance policy
Content Filter Policy template only allows the use of Dictionairs in the Subject/Body/Attachment section. There is no way to implement a compliance policy that uses a dictionary to scan just the subject line for matches.
While you could use a Pattern under "Text in this specific part of the message", many find RexEg overly complicated for this task.
Add Radio option/drop down in "Text in this specific part of the message" that allows user to select a dictionary.