Documentation on proximity filter

I've been trying to get Proximity Filter to work on my site for a while. I noticed that when i put the lat and lon in fields of the view that it doesn't effect the query. I then looked at the code itself and found that the filter expects the lat and lon to be in the $_GET. (location_views.module: Lines 931,932)

I was wondering if this was the way you intended for it to work, and if there was a place this module prefers to keep its documentation so that I can add to it.

Thanks.