Most programs ask for first and last names because they need to know both (a) the subject's full, hopefully unique* name and (b) the first name for informal gre

Most programs ask for first and last names because they need to know both (a) the subject's full, hopefully unique* name and (b) the first name for informal greetings (the "Howdy, Bob!" when you log in, or "Dear Bob" at the start of an automatic email). Can't this be solved for 99% of cases by switching from first/last name to asking for a subject's preferred full form name (which would be a string field which can contain arbitrary characters with some huge length limit) and a nickname (where users can write whatever they want the system to use in informal contexts)? *But any system using peoples' names as unique identifiers are in for a world of pain.