Paul Madsen has spoken on the SAML Enhanced Client Profile and his verdict is it’s like a donut. Now far be it from me to contradict Paul and his immeasurable skills in producing professional looking diagrams, but perhaps he should note the words of Mark Wahl in his comment that it looks like it “might have a ‘hole’ at its very center where it does not provide coverage?”

Paul, I suggest using carrots. Nice high profile colour, tapered end useful for zeroing in on the axis position, no holes.