where are iOS layout guidelines?

I have been trying to find a reference with details on the offset guidelines for subview layouts in iOS with no luck. I first looked in the IB guide, and in the section about layouts, it indicates that the IB guides (the blue lines) use guidelines supposedly described in detail in the iOS Mobile HIG, but I searched that document and didn't find any such guidelines.

Anyone know where it's specified, or am I just going to have to piddle with IB and write down numbers on sticky notes?