Why you shouldn't make stuff up

What exactly is the AP's problem? What makes it so hard for "Ask the Stylebook" to answer a simple (and perfectly reasonable) question without falling on its face?

"Mill" is not short for "millage." A mill, dating to the late 18th century, is a thousandth of a dollar. (As an 1811 OED cite puts it: "Dollars of 10 Dimes, 100 Cents, or 1000 Mills.") Apparently it made perfect sense to Thomas Jefferson in 1791: "At 20 cents pr lb it is 8 mills per dish." If you're old enough to remember S&H Green Stamps, you might have seen their cash value listed in mills.

"Millage" is newer; going by the earliest cites in the OED, it's about as old (1891) as "mill rate" (1895), and it's a perfectly sensible English noun formed in a perfectly sensible way. But here's the fun part, and the place where the AP missed the chance to do some real good, rather than proclaiming some bogus etymology. The three cites for "millage" include one from Columbus and one from the Freep, the only two cities* I've worked in where news stories talk about property tax in mills and millages.

The query comes from Lakeland, and the "few readers understand it" makes sense; most of my working life was in the South, and I'm used to talking about property taxes in cents per amount of assessed value. Like my first encounter with positive "anymore," mills were a WTF moment (you guys pay property tax in Green Stamps?) -- and to be fair, my puzzlement was often quite WTF for my new colleagues as well. Which is often how it is with regionalisms, and that's a point the AP would have done well to make.

I'm happy to agree that there's a single correct way to spell "mill" (even as I scorn the AP's insistence on "mic" over "mike" as the short form of "microphone"). That's the sort of thing stylebooks are there to do. But I don't see a point in solemnizing the whole thing with a made-up assertion whose sole purpose seems to be investing the AP with some sort of mystic authority that the AP's dictionary skills don't support.

As proclamations go, this one isn't actively harmful. It doesn't have the Orientalizing tendency of some loopier AP rulings about language -- proscribing the article "al" in Arabic names because it actually means "lord" or "mister," say** -- but it's dumb. It's contrary to everything the AP ought to be encouraging. Somebody asks a question about spelling, answer the spelling question. Then, if you want, explain how to figure out how old a word is and where it's used. If the Lakeland desk is wary of using a term that readers might not understand, give it a break. Give it some tools to help make that sort of decision.

But don't play Great and Powerful Oz. Especially when it's so easy to see behind the curtain.

* 200 miles apart, if you're scoring along at home. I read the Freep but have never worked there.
** 1986 only