Question : ovraw & ovkey

hi there,
some urls have extension "ovraw=", "ovkey=" & "ovmtc=". Is it for search engine tracking: click from a search result to a website, then track what's the terms and keywords? Which search engines use the tracking method? yahoo!? Is it unpaid search or "pay per click" advert?
thanks.

Answer : ovraw & ovkey

It is parameters from overture services. It used from search engines for ad-advertising
Google AdWords,Yahoo! Search Marketing,MSN adCenter uses them.
OVKEY will show the keyword (or phrase) you entered, e.g., Used Car
OVRAW will show the keyword (or phrase) a search user entered, e.g., Honda Used Cars
OVMTC will show the Traffic Type used to match your keyword with the user's keyword - Content, Standard, and Advanced