I think it is – in the (5Z) docs it says that “ignore” should only be used in procedural rules, which of course are now deprecated. I’m not sure what’s wrong with using them in non-procedural rules.
Anyway, I agree with Jim about the obscurity of the rulebook names; if you find a rule in the index page, there ought to be something telling you what rulebook it’s in (short of clicking the “unlist” button, which is a non-obvious hack if you don’t actually want to unlist the rule). When I was tinkering with this I had the devil’s own time figuring out what rulebook the “describe what’s on scenery supporters…” rule was in, before realizing that I didn’t need to know. And the rulebook often has a weird name (mine is “for printing a locale paragraph about”), so figuring out from the rule is non-trivial, at least the first time.