Well that's quite rude, you don't know me at all so you have no idea how much experience I have. And it's also quite contradictory... if the string is only rare

Well that's quite rude, you don't know me at all so you have no idea how much experience I have. And it's also quite contradictory... if the string is only rarely to be parsed by developers, why would "any web developer worth their salt" bother memorizing every browser's user agent? Experienced web developers don't have anything better to do than memorize a useless string they rarely have to work with?