lucy24 - 8:02 am on Mar 20, 2013 (gmt 0)
If you know that a particular element always occurs at the beginning of the UA string, then by all means anchor it. Then, if it isn't the very first thing, the server can stop looking. Closing anchors don't save any work-- the server can only read in one direction-- so use them only if the element must come last.
But most robots are not thoughtful enough to make it easy on your server.
it can be either (it can start or end with this name to find a match)
Or neither: the part you want can be sitting somewhere in the middle. And it doesn't have to be an exact full word, unless you explicitly say so.