Are you just looking for a description of the metric. You can try to look in the online help for Foglight which is typically very extensive and descriptive. If this is not adequite, just give a simple call or e-mail into Quest support (firstname.lastname@example.org). They'll be happy to answer questions such as these.
If you're having any problems finding a suitable answer you can shoot me an e-mail at jason dot hall at quest dot com and I'd be happy to do some digging.