SpaceJudas!

I've been working on a hidden files workflow recently (https://github.com/spooch56/alfred-hidden-files) and I came upon a very interesting metadata tag: kMDItemInvisibleFileType. Unlike the kMDItemFSInvisible tag, it's not listed in apple's metadata reference, indicating that it was added by an outside app. Based on a fairly limited survey of people, I've noticed that it only seems to appear on the computers with Alfred and so my best guess is that Alfred adds this metadata tag to allow md indexing of hidden files. Does anyone else know about this for certain? Do you guys all have this tag as well? I'd really like to share my workflow but not if it only works for me. Any information you guys have would be excellent.