I've seen in multiple fanfictions and other places the joke that Sirius and/or James wanted to name Harry Elvendork, stating that it was unisex. Is this from canon or Word of God, or just something created by the fans but spread widely?
And near the end:
It was written by Rowling for auctioning off for charity. I don't know whether most fans consider it canon. If you want to consider it canon, then do so. It doesn't say that they were going to name Harry Elvendork, but it does refer to it as unisex.
I've been in Harry Potter fandom since 2002 and I've never heard the term "Elvendork" in relation to Harry. Seems more appropriate for Legolas, were Legolas to have a ridiculous nickname.
There is this from Half-Blood Prince, though, which makes me laugh:
Also, Draco calling Harry "'The Boy Who Scored" ... or whatever it is they're calling you these days ...'" is a bit amusing.
I don't recall "Elvendork" in any of the Harry Potter books, nor has the term come up in any J.K. Rowling interview I've ever heard or read. I don't know how widely spread it really is, but if it is ubiquitous it's probably propogated by the fans at this point. That said, I encourage you all to throw your votes to Ike! :D