Nick 22 Aug, "" I discovered a while ago that help links in forms are created between the </label> and the form control, NOT at the end of the <label> element as I expected.
a) Currently Moodle has: <label for="x">Label</label> <a href="...">Help link</a> <input type="text" id="x" />

b) I think this order is preferable, to ensure that the link is accessible from forms mode - does this make sense?
<label for="x">Label <a href="...">Help link</a> </label> <input type="text" id="x" />
""
Chetz after testing, "The link within the label read perfectly in JAWS, whereas the link outside the label was ignored in forms mode."
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The attached patch modifies the MoodleQuickForm_Renderer::_elementTemplates array in 'lib/formslib.php'.
There don't appear to be any styling issues around this, so I will apply this immediately.