What is canon?

[prefectmarcus]

No: HPFGUIDX 39254

I don't think there is an offical statement.  The best is to say that 
there are different tiers.

The first tier consists of the published books.  These include the 
four novels (so far) and the two school books.  These are the 
standards.  Everything else is held up to compare with them.  If 
there is a conflict, the books win.

The second tier contains the interviews and chats by Rowling.  Most 
of what she says is canon.  However there are several instances that 
she seems to be speaking off-the-cuff.  So things must be taken with 
a grain of salt.

The third tier are the interpetations of the books, such as the films 
and the book art.  While Rowling does have an unusual amount of 
control, she doesn't control everything.  She allows a great deal of 
artistic license with her works. The book specifically states that 
the hole behind the Fat Lady is round, yet the American chapter 
picture is square.  Another example is the wide variety of placements 
of Harry's scar.

Marcus