Can't input a Tag whose name is a subset of an existing tag

(Incomplete Feature, Investigate , Priority: Medium, Test Status: No automated tests yet , Reported By Justin du Coeur, )
Summary: As an example, the Features has an existing Tag "Tag Sets". I can't create a new Tag named "Sets".
I suspect this is a design flaw in Manifest, and will be some hassle to fix, but I'll have to investigate further. Hopefully there is just some flag I can set to fix this.