Rules seem to ignore brackets

When possible spam comes through our filter it gets marked with different tags in the subject. One Such tag is [MARKETING]. When I make a rule to move all new mail with that in the subject to a special folder, it also puts any new mail with the word marketing (without the brackets) in in that folder. How do I get it to honor the brackets?

Running 14.2.1 build 124595 client.
Post office