h:button must support the disabled attribute (spec rev A)

h:button currently does not support the disabled attribute, because it is not listed in the attributes of h:button in the VDL docs. However it is mentioned in the description of h:button in the VDL docs: "If the "disabled" attribute is specified, do not render the "onclick" element and assign the "disabled" attribute a value of true."

Furthermore h:link also supports this attribute.