+ Sets an authentication string for a given database. For Z39.50,
+ this is carried as part of the Initialize Request. In order to carry
+ the information in the "open" elements, separate
+ username and password with a slash (In Z39.50 it is a VisibleString).
+ In order to carry the information in the idPass elements, separate
+ username term, password term and, optionally, a group term with a
+ single blank.
+ If three terms are given, the order is
+ <emphasis>user, group, password</emphasis>.
+ If only two terms are given, the order is
+ <emphasis>user, password</emphasis>.
+ </para>
+ <para>
+ For HTTP based procotols, such as SRU and Solr, the authentication
+ string includes a username term and, optionally, a password term.
+ Each term is separated by a single blank. The
+ authentication information is passed either by HTTP basic
+ authentication or via URL parameters. The mode is operation is
+ determined by <literal>pz:authentication_mode</literal> setting.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>pz:authentication_mode</term>
+ <listitem>
+ <para>
+ Determines how authentication is carried in HTTP based protocols.
+ Value may be "<literal>basic</literal>" or "<literal>url</literal>".