Whenever I tried to be that concise in a rules text, pretty soon someone would pop up complaining that "it" would be too ambiguous. Therefore I prefer my "that something" texts regardless of the slightly awkward English.
Well, let's see if anyone misunderstands. :)
That's why I proposed a definition including labels for the things referred to--it strikes me as the best way of avoiding both ambiguity and awkwardness. If this proposed alternative is not exactly equivalent to the correct definition (this still isn't clear to me), can it easily be modified to make it correct?