I\'ve always frowned upon skipping heading levels in HTML documents, especially for reasons of screenreader accessibility. Additionally the requirement that a page\'s structure
This topic came up in a WebAIM presentation I attended recently and they recommended you not skip heading levels. Their reasoning was that screen readers typically offer a shortcut that brings up a list of all headings within the page as a means of user navigation.
The scenario they described was that if a person using a screen reader was cycling through the headings (ex. h1, then h2's then h3's) and the reader reported nothing for a given level of heading (h4's in this case), then the user would likely stop cycyling through the headings under the assumption that there are no more headings (potentially missing any h5's and h6's).
So, in effect, you risk creating a usability problem if you skip levels!