Ruiz is only the paternal surname, and Picasso being the maternal surname. Spanish naming conventions are differént from most other Western traditions, but just including Ruiz wouldn't be identifying the middle name (in this case names) at all. Per the contest rules, the winning post must identify the full name, not just the first, or last, but middle name as well. Sorry LaurieOK, this kind of thing sucks and it just happened in last month's contest, but I was just making certain that I followed the rules.
