I have been looking at the searches.dat file which stores the current search information including search terms and results. I notice that before each search term is a 16 byte string of hex, which I thought was a hash of some kind. But I notice that the same search term generates completely different strings of this 16 byte value. So either it is not a hash or if it is it is unique to the search.

Can anyone give me a hint of what this 16 byte string is?