Reg Z defined terms, part 1 (probably)

I know there was talk of lxml and also not extending the grammar but it seemed like the logical first step. I've only really looked at 1026.2 so far and have aimed to capture things like:

(2) <E T="03">Advertisement</E> means a commercial message in any medium that promotes, directly or indirectly, a credit transaction.

(4) <E T="03">Billing cycle</E> or <E T="03">cycle</E> means the interval between the days or dates of regular periodic statements. These intervals shall be equal and no longer than a quarter of a ...