How do I conditionalize a header/footer?
I am using a customized axdocbook as a MIL-STD technical bulletin.
I need the header/footer to populate the classification level of the individual pdf page. If any element has the attribute classification=secret, I need SECRET to appear in the header/footer. If no elements on the page are secret (meaning they do not have a classification attribute or have classification=unclassified), I need SECRET<newline/>(THIS PAGE IS UNCLASSIFIED) to appear in the header footer.
I have been able to conditionalize the gentext for the individual elements based on this attribute (to apply (S) or (U) before the element's content and so on). However, I do not know how to conditionalize the content in a header or footer.

