+ <varlistentry><term>Check-Valid-Until</term>
+ <listitem><para>Security related option defaulting to true as an
+ expiring validation for a Release file prevents longtime replay attacks
+ and can e.g. also help users to identify no longer updated mirrors -
+ but the feature depends on the correctness of the time on the user system.
+ Archive maintainers are encouraged to create Release files with the
+ <literal>Valid-Until</literal> header, but if they don't or a stricter value
+ is volitional the following <literal>Max-ValidTime</literal> option can be used.
+ </para></listitem>
+ </varlistentry>
+
+ <varlistentry><term>Max-ValidTime</term>
+ <listitem><para>Seconds the Release file should be considered valid after
+ it was created. The default is "for ever" (0) if the Release file of the
+ archive doesn't include a <literal>Valid-Until</literal> header.
+ If it does then this date is the default. The date from the Release file or
+ the date specified by the creation time of the Release file
+ (<literal>Date</literal> header) plus the seconds specified with this
+ options are used to check if the validation of a file has expired by using
+ the earlier date of the two. Archive specific settings can be made by
+ appending the label of the archive to the option name.
+ </para></listitem>
+ </varlistentry>
+