ALERT: Incorrectly ordered headings

I was doing some work for the BBC the other day. This is fairly commonplace amongst freelance web developers; at some point in your peripatetic career you get your call-up papers for Auntie. One of the requirements was that:

“ 4.3. Heading elements MUST be ordered properly. H2 elements should follow H1 elements in the HTML flow, H3 elements should follow H2 elements, etc.” (from Future Media Standards & Guidelines).

And this was backed up by the WAVE toolbar add-on for Firefox: ALERT: Incorrectly ordered headings

But I think it's pretty unworkable. There are many instances where headings don't follow in such a hierarchical order. For example, not all articles will have a sub-title, though they may all have a reference:

h1 Title
h2 Subtitle
h3 Reference

There are four ways around this:

1. Create a different style for instances where this is no subtitle.
2. Insert a hidden subtitle that is not visible (as happens someplaces on the Radio 4 site).
3. Use a specific class rather than the semantic HTML h3 to describe the reference.
4. Ignore it.

Number 1 is unworkable, number 2 is a waste of time, number 3 goes against the grain of cleanly structured HTML. Leaving number 4, which funnily enough I agree with.

It is worth looking at why this is both a requirement and an issue. Apparently it is for accessibilty issues, that it is easier for a person using a screen reader to make sense of a page with "properly ordered" headings. Again, I disagree. The semantic structure should be the same for sighted and visually-impaired users. This is a supposition on my part, never having used a screen reader for any length of time. Neither have I read any research on the matter.

I'd be interested to hear your opinions.