[This][1] book by Manfred Knebusch starts with the limerick *A Mathematician Said Who Can Quote Me a Theorem that’s True? For the ones that I Know Are Simply not So, When the Characteristic is Two!* It gives a uniform treatment of quadratic forms in all characteristics including two. [1]: http://www-nw.uni-regensburg.de/~.knm22087.mathematik.uni-regensburg.de/book.pdf