expiry doubt

Hi,
    I've got a question on the expiration date of the policies. What I evinced from P3P specs is what follows:

1) Policy Reference File : if the POLICY-REFERENCES node has the EXPRY node as a child, then - for all the policy references that follow - the expiration date is computed using the info carried in the EXPIRY node. Otherwise, such policy references have a 24-hours validity.
2) Policy: if the POLICIES node (that MUST appear in any xml file representing a policy) has the EXPRY node as a child, then the policy expiration date is computed using the info carried in the EXPIRY node. Otherwise, the policy has a 24-hours validity.

So, in both cases, we have 2 ways to compute the expiration of a policy/policy ref file.
I've encountered a Policy Ref File with the following structure, that made me think about a third way:

<POLICY-REFERENCES>
<EXPIRY max-age="86400 " />
<POLICY-REF about="#XYZ">
<INCLUDE>/*</INCLUDE>
</POLICY-REF>
</POLICY-REFERENCES>
<POLICIES xmlns="http://www.w3.org/2002/01/P3Pv1">
<POLICY name="XYZ">
.....
....
</POLICY>
</POLICIES>

The POLICIES node doesn't have an EXPIRY node, so - according to P3P Recommendation - all the POLICY it embeds should be treated as having a 24-hours validity.
However, I was wondering if - since the POLICIES node is inside the Policy Reference File - we should use the EXPIRY node inside the POLICY-REFERENCES to compute the POLICY validity.
Maybe this sounds crazy, and it doesn't make great sense to me too, but I would like to have this point clear.

Thanks a lot