On the subject of customary forms of address, I would just like to point out that while address by given name is the "norm" in the US, in actual practice it varies quite a bit from individual to individual.  I know a gentleman whose first name is "John" and middle name is "David"; he goes by "J. D.".  I met him in college, and through him also met one James Cochrane, who went exclusively by "Cochrane".  Nobody called him "James" at the time.  (He goes by "James" more commonly now that he's a grown man, husband, and father... but he has never been a "Jim" or "Jimmy".)  My rooomate at the time had first name Shannon, middle name Keith, and went by "Keith", and was listed as "S. Keith" on official documents wherever he could get away with it.  That includes the telephone directory, and he frequently got calls for a different "S. Keith" of the same last name in our city - a reporter for the local newspaper.  Even further removed from the supposed custom was our professor William Augustus Baird, who went by "gus" - and insisted upon the lowercase |g| in written form.  But at that point you have entered the realm of nicknames, which may or may not bear any relationship to someone's real name at all. 

Most databases with information about people nowadays have a field in the record for "preferred name" to capture these peculiarities.

I find the common European practice of restricting the set of names you can give your child utterly ridiculous.  Many cultures find the idea of giving their child a reused name abhorrent; aside from not moving to those countries, they would seem to be out of luck.  Of course,  if the US did have such a system, Nicholas Cage would have been prevented from naming his child Kal-El, and Chipper Jones from naming his child after a baseball stadium, but you can't let a few good outcomes bias you toward laws that restrict freedom.  It's not the American Way. :)