Well, it turns out you can do that. From The LABEL element in the HTML 4.01 specification:
The LABEL element may be used to attach information to controls. Each LABEL element is associated with exactly one form control.
The for attribute associates a label with another control explicitly: the value of the for attribute must be the same as the value of the id attribute of the associated control element. More than one LABEL may be associated with the same control by creating multiple references via the for attribute.
Sounds great, doesn’t it? A quick check in graphical web browsers shows that they associate multiple labels with the input field (as evidenced by the input field gaining focus when either label is clicked). But what about screen readers? It would be so useful if this would work…
Unfortunately, and perhaps unsurprisingly, it looks like it doesn’t quite work as well as you’d hope. I mentioned this briefly in Use the label element to make your HTML forms accessible, but I think it’s worth bringing up again since full support for multiple labels would help us make forms more accessible to screen reader users while keeping visual designers happy.
I am far from an expert user when it comes to screen readers, but I’ve done some limited testing with mostly disappointing results.
Apple VoiceOver does not recognise more than one label element associated with a form control and reads only the label that comes first in the document’s source order.
JAWS and Window-Eyes both do the opposite and read only the last label when an input field gains focus.
The only screen reader of those that I tested that does handle multiple labels is Fire Vox.
The exact results may obviously depend on user configuration and reading modes, and there may be other screen readers that get it right, but these results indicate that screen reader behaviour is too inconsistent for multiple labels to be a reliable technique.
