The reference does not mention that <s:validateAll> does not validate input fields that already have another validator assigned.

Worse, it even says

This tag simply adds an <s:validate> to every input in the form.

which is incorrect. <s:validate> is applied even if a component has another validator.

So, could somebody please update the reference and the description in the taglib.
That would have saved me from looking at the seam sources to determine wether this is a bug or intended behaviour.