+
+
+ <sect3 id="querymodel-query-languages-pqf">
+ <title>Prefix Query Format (PQF)</title>
+ <para>
+ Index Data has defined a textual representation in the
+ <ulink url="&url.yaz.pqf;">Prefix Query Format</ulink>, short
+ <emphasis>PQF</emphasis>, which maps
+ one-to-one to binary encoded
+ <emphasis>type-1 RPN</emphasis> queries.
+ PQF has been adopted by other
+ parties developing Z39.50 software, and is often referred to as
+ <literal>Prefix Query Notation</literal>, or in short
+ <literal>PQN</literal>. See
+ <xref linkend="querymodel-pqf"/> for further explanations and
+ descriptions of Zebra's capabilities.
+ </para>
+ </sect3>
+
+ <sect3 id="querymodel-query-languages-cql">
+ <title>Common Query Language (CQL)</title>