The wire service has made it easier -- at a cost of $49.99 -- to follow AP style without checking a separate website or reference book. The AP stylebook costs $19.95 (less for newspaper members); online access to the AP stylebook is $25 for a single license, $200 for 10 licenses.
Here's how it works:

Your documents are checked automatically in Microsoft Word and as you type, each proposed correction is clearly highlighted in the document and shows you the corresponding AP Stylebook rule, so you always know why something was corrected.

Easy-to-understand features are similar to other proofing tools, including Ignore, Ignore All, Change, Change All, Auto Correct and Add Comment.

Stylebook product manager Colleen Newvine explains the pricing:

This product has been in the works for quite some time. The heavy lifting involved in having linguists dissect each Stylebook rule to look for multiple ways people might get it wrong so the software can recognize a mistake and suggest the right way is monumental.

As such, we consider this a premium product that delivers more value than the traditional spiral-bound book.

We benchmarked against a variety of other Word plug ins to get a sense of what the marketplace looked like, in addition to comparing the increased value of automation over manually looking up style listings in the book or Stylebook Online.

I think some customers will use StyleGuard in addition to other Stylebook products -- the book, a Stylebook Online subscription or a Stylebook Mobile app -- while others might find it’s robust enough to replace the other resource.