What is a metadata specialist?

I saw a job posting for a Metadata Specialist on one of the library listserv's I am on.

Just curious as to what that sort of job entails.

The way metadata was explained to me is this:

It's kind of like an electronic fingerprint or trail that attaches itself to a document. I.E., say you e-mail a contract to a client, your client makes changes to it and sends it back... you have some of your client's network/IP info attached to the doc and vise versa, leaving your respective networks vulnerable to others who may receive the doc electronically.

Again, this could be the wrong info... I'm just passing along what I was told.