valid after it was created (indicated by the <literal>Date</literal> header).
Use this if you need to use a seldomly updated (local) mirror of a more
regular updated archive with a <literal>Valid-Until</literal> header
valid after it was created (indicated by the <literal>Date</literal> header).
Use this if you need to use a seldomly updated (local) mirror of a more
regular updated archive with a <literal>Valid-Until</literal> header