Or maybe it requires specific knowledge of obscure names like Adobe Reader. Or did I miss something and Adobe started charging for Reader once there were double

Or maybe it requires specific knowledge of obscure names like Adobe Reader. Or did I miss something and Adobe started charging for Reader once there were double - digit numbers of free alternatives including those built into the browsers? Heck, do Chrome or Firefox actually register with the system to handle PDFs? Wouldn't surprise me if they did.