Receptional_Andy - 8:24 pm on May 10, 2008 (gmt 0)

Today I noticed an additional parameter being used in my Google search URLs, originating from a hidden text field with the name 'hs'.

This field changes on each pageload, and consists of three random characters - a letter or a number, e.g. pCv or 4yu.

I'm aware of the usage of most of the Google search parameters, but I've never seen this one before.

A typical URL for me would be www.google.com/search?hl=en&client=firefox-a&rls=org.mozilla%3Aen-GB%3Aofficial&hs=pcV&q=widget&btnG=Search

hl - interface language
client and rls - supplied by software manufacturers to track usage
q - the keyword
btnG - I hit the search button
hs?

Seemingly, this variable appears for any search where the parameter 'client' is set to 'firefox' (plus any other characters) appears (e.g. &client=firefoxasdas will trigger it). I couldn't find any other parameters or values that had the same effect (e.g. sourceid=opera and other tracking-type info).

Does anyone have any idea what this might be used for?