The section on Box Model Properties introduces a large number of new properties which are very different from all other CSS properties in that they don't have independent computed values, because their computed values mirror another CSS property. While this is expressed in the prose, it seems like it should be expressed in the propdef table, since other specifications will (hopefully) be introducing similar properties, and it would be good to have a consistent notation for introducing them rather than doing so with prose that may come over time to have normative differences.

I got here from w3ctag/design-reviews#286.