Hi Oscar. I'm thinking that their question may have been prompted by last year's Justice Department ruling, mandating WCAG 2.1 AA standards for government groups:
A little bit of web browsing led me to this page, from the Web Accessibility Initiative:
The page is titled Easy Checks - A First Review of Web Accessibility. Here's a quote from the page:
"These checks cover just a few accessibility issues and are designed to be quick and easy, rather than definitive. A web page could seem to pass these checks, yet still have significant accessibility barriers. More robust assessment is needed to evaluate accessibility comprehensively."
"Just a few" accessibility issues? There's a LOT of stuff on that page. :-/
My temptation here: just go with WAVE. Put a recommendation for WAVE somewhere in the Guide, with a warning that no automated accessibility checker can catch all accessibility issues. *shrug*
-Joseph DiMuro