Raw Defending only works on swords, So bye bye defending Armour spikes
"Defending: A defending weapon allows the wielder to transfer some or all of the sword’s enhancement bonus to his AC as a bonus that stacks with all others. As a free action, the wielder chooses how to allocate the weapon’s enhancement bonus at the start of his turn before using the weapon, and the effect to AC lasts until his next turn."
"Swords enchantment bonus"
Also worded this way in my pdf, and my downloaded copy of the system reference document. Since raw is sacred and I laugh at that, I felt this fitting to point out.
Of course that is the 3.5 version Pathfinder in its near infinite glory caught on.