+ The rules for PQF APT mapping are rather tricky to grasp in the
+ first place. We deal first with the rules for deciding which
+ internal register or string index to use, according to the use
+ attribute or access point specified in the query. Thereafter we
+ deal with the rules for tetermining the correct structure type of
+ the named register.
+ </para>
+
+ <sect3 id="querymodel-pqf-apt-mapping-accesspoint">
+ <title>Mapping of PQF APT access points</title>
+ <para>
+ Zebra understands four fundamental different types of access
+ points, of which only the
+ <emphasis>numeric use attribute</emphasis> type access points
+ are defined by the <ulink url="&url.z39.50;">Z39.50</ulink>
+ standard.
+ All other access point types are Zebra specific, and non-portable.
+ </para>
+
+ <table id="querymodel-zebra-mapping-accesspoint-types"
+ frame="all" rowsep="1" colsep="1" align="center">
+
+ <caption>Acces point name</caption>
+ <thead>
+ <tr>
+ <td>Acess Point</td>
+ <td>Type</td>
+ <td>Grammar</td>
+ <td>Notes</td>
+ </tr>
+ </thead>
+ <tbody>
+ <tr>
+ <td>Use attibute</td>
+ <td>numeric</td>
+ <td>[1-9][1-9]*</td>
+ <td>directly mapped to string index name</td>
+ </tr>
+ <tr>
+ <td>String index name</td>
+ <td>string</td>
+ <td>[a-zA-Z](\-?[a-zA-Z0-9])*</td>
+ <td>normalized name is used as internal string index name</td>
+ </tr>
+ <tr>
+ <td>Zebra internal index name</td>
+ <td>zebra</td>
+ <td>_[a-zA-Z](_?[a-zA-Z0-9])*</td>
+ <td>hardwired internal string index name</td>
+ </tr>
+ <tr>
+ <td>XPATH special index</td>
+ <td>XPath</td>
+ <td>/.*</td>
+ <td>special xpath search for GRS indexed records</td>
+ </tr>
+ </tbody>
+ </table>
+
+ <para>
+ <literal>Attribute set names</literal> and
+ <literal>string index names</literal> are normalizes
+ according to the following rules: all <emphasis>single</emphasis>
+ hyphens <literal>'-'</literal> are stripped, and all upper case
+ letters are folded to lower case.</para>
+
+ <para>
+ <emphasis>Numeric use attributes</emphasis> are mapped
+ to the Zebra internal
+ string index according to the attribute set defintion in use.
+ The default attribute set is <literal>Bib-1</literal>, and may be
+ omitted in the PQF query. According to normalization and numeric
+ use attribute mapping, it follows that the following
+ PQF queries are considered equivalent (assuming the default
+ configuration has not been altered):
+ <screen>
+ Z> find @attr 1=Body-of-text serenade
+ Z> find @attr 1=bodyoftext serenade
+ Z> find @attr 1=BodyOfText serenade
+ Z> find @attr 1=bO-d-Y-of-tE-x-t serenade
+ Z> find @attr 1=1010 serenade
+ Z> find @attrset Bib-1 @attr 1=1010 serenade
+ Z> find @attrset bib1 @attr 1=1010 serenade
+ Z> find @attrset Bib1 @attr 1=1010 serenade
+ Z> find @attrset b-I-b-1 @attr 1=1010 serenade
+ </screen>
+ </para>
+
+ <para>
+ The <emphasis>numerical</emphasis>
+ <literal>use attributes (type 1)</literal>
+ are interpreted according to the
+ attribute sets which have been loaded in the
+ <literal>zebra.cfg</literal> file, and are matched against specific
+ fields as specified in the <literal>.abs</literal> file which
+ describes the profile of the records which have been loaded.
+ If no use attribute is provided, a default of Bib-1 Any is
+ assumed.
+ The predefined <literal>use attribute sets</literal>
+ can be reconfigured by tweaking the configuration files
+ <filename>tab/*.att</filename>, and
+ new attribute sets can be defined by adding similar files in the
+ configuration path <literal>profilePath</literal> of the server.
+ </para>
+
+ <para>
+ <literal>String indexes</literal> can be acessed directly,
+ independently which attribute set is in use. These are just
+ ignored. The above mentioned name normalization applies.
+ <literal>String index names</literal> are defined in the
+ used indexing filter configuration files, for example in the
+ <literal>GRS</literal>
+ <filename>*.abs</filename> configuration files, or in the
+ <literal>alvis</literal> filter XSLT indexing stylesheets.
+ </para>
+
+ <para>
+ <literal>Zebra internal indexes</literal> can be acessed directly,
+ according to the same rules as the user defined
+ <literal>string indexes</literal>. The only difference is that
+ <literal>Zebra internal indexe names</literal> are hardwired,
+ all uppercase and
+ must start with the character <literal>'_'</literal>.
+ </para>
+
+ <para>
+ Finally, <literal>XPATH</literal> access points are only
+ available using the <literal>GRS</literal> filter for indexing.
+ These acees point names must start with the character
+ <literal>'/'</literal>, they are <emphasis>not
+ normalized</emphasis>, but passed unaltered to the Zebra internal
+ XPATH engine. See <xref linkend="querymodel-use-xpath"/>.
+