I'm told that the codex authors aren't the ones that layout the print for the book - and that when they send off the content to the layout team, the layout team has to "make things fit" on pages in order to be printed. Sometimes this means chopping off rules and such.
I think what these FAQs are - are clarifications stemming from this "pruning" that takes place just prior to print.
It sounds ridiculous to me too.