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
- instead of competely disabling the expiration date checking.
+ instead of completely disabling the expiration date checking.
Archive specific settings can and should be used by appending the label of
the archive to the option name.
</para></listitem>