added section on explain, search, scan and on PQN

[idzebra-moved-to-github.git] / doc / querymodel.xml

diff --git a/doc/querymodel.xml b/doc/querymodel.xml
index bed7a2e..71cca4d 100644 (file)
--- a/doc/querymodel.xml
+++ b/doc/querymodel.xml
@@ -1,5 +1,5 @@
  <chapter id="querymodel">
  <chapter id="querymodel">

-  <!-- $Id: querymodel.xml,v 1.6 2006-06-15 13:41:49 marc Exp $ -->
+  <!-- $Id: querymodel.xml,v 1.8 2006-06-16 12:54:55 marc Exp $ -->

   <title>Query Model</title>
   
   <sect1 id="querymodel-overview">
   <title>Query Model</title>
   
   <sect1 id="querymodel-overview">

@@ -14,14 +14,21 @@
      to the international standards 
      <ulink url="&url.z39.50;">Z39.50</ulink> and
      <ulink url="&url.sru;">SRU</ulink>,
      to the international standards 
      <ulink url="&url.z39.50;">Z39.50</ulink> and
      <ulink url="&url.sru;">SRU</ulink>,

-     and implement the query model defined there.
-     Unfortunately, the Z39.50 query model has only defined a binary
+     and implement the 
+     <literal>type-1 Reverse Polish Notation (RPN)</literal> query
+     model defined there.
+     Unfortunately, this model has only defined a binary

      encoded representation, which is used as transport packaging in
      the Z39.50 protocol layer. This representation is not human
      readable, nor defines any convenient way to specify queries. 
     </para>
      encoded representation, which is used as transport packaging in
      the Z39.50 protocol layer. This representation is not human
      readable, nor defines any convenient way to specify queries. 
     </para>

-   <!-- tell about RPN - include link to YAZ 
-        url.yaz.pqf -->
+    <para>
+     Since the <literal>type-1 (RPN)</literal> 
+     query structure has no direct, useful string
+     representation, every origin application needs to provide some
+     form of mapping from a local query notation or representation to it.
+     </para>
+

 
    <sect3 id="querymodel-query-languages-pqf">
     <title>Prefix Query Format (PQF)</title>
 
    <sect3 id="querymodel-query-languages-pqf">
     <title>Prefix Query Format (PQF)</title>

@@ -29,50 +36,110 @@
    <para>
      Index Data has defined a textual representaion in the 
      <literal>Prefix Query Format</literal>, short
    <para>
      Index Data has defined a textual representaion in the 
      <literal>Prefix Query Format</literal>, short

-     <literal>PQF</literal>, which then has been adopted by other
-     parties developing Z39.50 software. It is also often referred to as
+     <literal>PQF</literal>, which mappes 
+      <literal>one-to-one</literal> to binary encoded  
+      <literal>type-1 RPN</literal> query packages.
+      It 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>Prefix Query Notation</literal>, or in short 

-     <literal>PQN</literal>, and is thoroughly explained in       
-     <xref linkend="querymodel-pqf"/>. 
+     <literal>PQN</literal>. See       
+     <xref linkend="querymodel-pqf"/> for further explanaitions and
+     descriptions of Zebra's capabilities.  

     </para>
    </sect3>    
 
     </para>
    </sect3>    
 

-
-   <!-- PQF/RPN is natively supported. CQL is NOT . So we need a map -->

    <sect3 id="querymodel-query-languages-cql">
     <title>Common Query Language (CQL)</title>
    <sect3 id="querymodel-query-languages-cql">
     <title>Common Query Language (CQL)</title>

-   <para>
-     In addition, Zebra can be configured to understand and map the 
-     <literal>Common Query Language</literal>
-     (<ulink url="&url.cql;">CQL</ulink>)
-     to PQF. See an introduction on the mapping to the internal query
-     representation in  
+     <para>
+      The query model of the   <literal>type-1 RPN</literal>,
+      expressed in <literal>PQF/PQN</literal> is natively supported. 
+      On the other hand, the default <literal>SRU</literal>
+      webservices <literal>Common Query Language</literal>
+     <ulink url="&url.cql;">CQL</ulink> is not natively supported.
+     </para>
+     <para>
+     Zebra can be configured to understand and map CQL to PQF. See

      <xref linkend="querymodel-cql-to-pqf"/>.
     </para>
    </sect3>    
  
    </sect2>
 
      <xref linkend="querymodel-cql-to-pqf"/>.
     </para>
    </sect3>    
  
    </sect2>
 

-   <sect2 id="querymodel-query-types">
-    <title>Query types</title>
+   <sect2 id="querymodel-operation-types">
+    <title>Operation types</title>

     <para>
     <para>

+     Zebra supports all of the three different
+     <literal>Z39.50/SRU</literal> operations defined in the
+     standards: <literal>explain</literal>, <literal>search</literal>, 
+     and <literal>scan</literal>. A short description of the
+     functionality and purpose of each is quite in order here. 

     </para>
 
     </para>
 

-    <sect3 id="querymodel-query-type-explain">
-     <title>Explain Queries</title>
+    <sect3 id="querymodel-operation-type-explain">
+     <title>Explain Operation</title>
+     <para>
+      The <emphasis>syntax</emphasis> of Z39.50/SRU queries is
+      well known to any client, but the specific
+      <emphasis>semantics</emphasis> - taking into account a
+      particular servers functionalities and abilities - must be
+      discovered from case to case. Enters the 
+      <literal>explain</literal> operation, which provides the means
+      for learning which  
+      <emphasis>fields</emphasis> (also called
+      <emphasis>indexes</emphasis> or <emphasis>access points</emphasis>
+      are provided, which default parameter the server uses, which
+      retrieve document formats are defined, and which specific parts
+      of the general query model are supported.      
+     </para>
+     <para>
+      The Z39.50 embeddes the <literal>explain</literal> operation
+      by perfoming a 
+      <literal>search</literal> in the magic 
+      <literal>IR-Explain-1</literal> database;
+      see <xref linkend="querymodel-exp1"/>. 
+     </para>
+     <para>
+      In SRU, <literal>explain</literal> is an entirely  seperate
+      operation, which returns an  <literal>Zeerex
+      XML</literal> record according to the 
+      structure defined by the protocol.
+     </para>

      <para>
      <para>

+      In both cases, the information gathered through
+      <literal>explain</literal> operations can be used to
+      auto-configure a client user interface to the servers
+      capabilities.  

      </para>
     </sect3>
 
      </para>
     </sect3>
 

-    <sect3 id="querymodel-query-type-search">
-     <title>Search Queries</title>
+    <sect3 id="querymodel-operation-type-search">
+     <title>Search Operation</title>

      <para>
      <para>

+      Search and retrieve interactions are the raison d'être. 
+      They are used to query the remote database and
+      return search result documents.  Search queries span from
+      simple free text searches to nested complex boolean queries,
+      targeting specific indexes, and possibly enhanced with many
+      query semantic specifications. Search interactions are the heart
+      and soul of Z39.50/SRU servers.

      </para>
     </sect3>
 
      </para>
     </sect3>
 

-    <sect3 id="querymodel-query-type-scan">
-     <title>Scan Queries</title>
+    <sect3 id="querymodel-operation-type-scan">
+     <title>Scan Operation</title>

      <para>
      <para>

+      The <literal>scan</literal> operation is a helper functionality,
+       which operates on one index or access point a time. 
+     </para>
+     <para>
+      It provides
+      the means to investigate the content of specific indexes.
+      Scanning an index returns a handfull of terms actually fond in
+      the indexes, and in addition the <literal>scan</literal>
+      operation returns th enumber of documents indexed by each term.
+      A search client can use this information to propose proper
+      spelling of search terms, to auto-fill search boxes, or to 
+      display  controlled vocabularies.

      </para>
     </sect3>
 
      </para>
     </sect3>
 

@@ -98,7 +165,7 @@
      may start with one specification of the 
      <emphasis>attribute set</emphasis> used. Following is a query
      tree, which 
      may start with one specification of the 
      <emphasis>attribute set</emphasis> used. Following is a query
      tree, which 

-     consists of <emphasis>atomic query parts</emphasis>, eventually
+     consists of <emphasis>atomic query parts (APT)</emphasis>, eventually

      paired by <emphasis>boolean binary operators</emphasis>, and 
      finally  <emphasis>recursively combined </emphasis> into 
      complex query trees.   
      paired by <emphasis>boolean binary operators</emphasis>, and 
      finally  <emphasis>recursively combined </emphasis> into 
      complex query trees.   

@@ -119,7 +186,9 @@
       </note>
      </para>
      
       </note>
      </para>
      

-     <table id="querymodel-attribute-sets-table">
+     <table id="querymodel-attribute-sets-table"
+      frame="all" rowsep="1" colsep="1" align="center">
+

       <caption>Attribute sets predefined in Zebra</caption>
        <!--
        <thead>
       <caption>Attribute sets predefined in Zebra</caption>
        <!--
        <thead>

@@ -128,7 +197,7 @@
        -->
        <tbody>
         <tr>
        -->
        <tbody>
         <tr>

-         <td><emphasis>exp-1</emphasis></td>
+         <td><literal>exp-1</literal></td>

          <td><literal>Explain</literal> attribute set</td>
          <td>Special attribute set used on the special automagic
           <literal>IR-Explain-1</literal> database to gain information on
          <td><literal>Explain</literal> attribute set</td>
          <td>Special attribute set used on the special automagic
           <literal>IR-Explain-1</literal> database to gain information on

@@ -136,7 +205,7 @@
           and semantics.</td>
         </tr>
         <tr>
           and semantics.</td>
         </tr>
         <tr>

-         <td><emphasis>bib-1</emphasis></td>
+         <td><literal>bib-1</literal></td>

          <td><literal>Bib1</literal> attribute set</td>
          <td>Standard PQF query language attribute set which defines the
           semantics of Z39.50 searching. In addition, all of the
          <td><literal>Bib1</literal> attribute set</td>
          <td>Standard PQF query language attribute set which defines the
           semantics of Z39.50 searching. In addition, all of the

@@ -144,7 +213,7 @@
           processing</td>
         </tr>
         <tr>
           processing</td>
         </tr>
         <tr>

-         <td><emphasis>gils</emphasis></td>
+         <td><literal>gils</literal></td>

          <td><literal>GILS</literal> attribute set</td>
          <td>Extention to the <literal>Bib1</literal> attribute set.</td>
         </tr>
          <td><literal>GILS</literal> attribute set</td>
          <td>Extention to the <literal>Bib1</literal> attribute set.</td>
         </tr>

@@ -159,7 +228,9 @@
       using the standard boolean operators into new query trees.
      </para>
      
       using the standard boolean operators into new query trees.
      </para>
      

-     <table id="querymodel-boolean-operators-table">
+     <table id="querymodel-boolean-operators-table"
+      frame="all" rowsep="1" colsep="1" align="center">
+

       <caption>Boolean operators</caption>
        <!--
        <thead>
       <caption>Boolean operators</caption>
        <!--
        <thead>

@@ -167,19 +238,19 @@
       </thead>
        -->
        <tbody>
       </thead>
        -->
        <tbody>

-        <tr><td><emphasis>@and</emphasis></td>
+        <tr><td><literal>@and</literal></td>

          <td>binary <literal>AND</literal> operator</td>
          <td>Set intersection of two atomic queries hit sets</td>
         </tr>
          <td>binary <literal>AND</literal> operator</td>
          <td>Set intersection of two atomic queries hit sets</td>
         </tr>

-        <tr><td><emphasis>@or</emphasis></td>
+        <tr><td><literal>@or</literal></td>

          <td>binary <literal>OR</literal> operator</td>
          <td>Set union of two atomic queries hit sets</td>
         </tr>
          <td>binary <literal>OR</literal> operator</td>
          <td>Set union of two atomic queries hit sets</td>
         </tr>

-        <tr><td><emphasis>@not</emphasis></td>
+        <tr><td><literal>@not</literal></td>

          <td>binary <literal>AND NOT</literal> operator</td>
          <td>Set complement of two atomic queries hit sets</td>
         </tr>
          <td>binary <literal>AND NOT</literal> operator</td>
          <td>Set complement of two atomic queries hit sets</td>
         </tr>

-        <tr><td><emphasis>@prox</emphasis></td>
+        <tr><td><literal>@prox</literal></td>

          <td>binary <literal>PROXIMY</literal> operator</td>
          <td>Set intersection of two atomic queries hit sets. In 
           addition, the intersection set is purged for all 
          <td>binary <literal>PROXIMY</literal> operator</td>
          <td>Set intersection of two atomic queries hit sets. In 
           addition, the intersection set is purged for all 

@@ -237,12 +308,13 @@
     
     
     <sect3 id="querymodel-atomic-queries">
     
     
     <sect3 id="querymodel-atomic-queries">

-     <title>Atomic queries</title>
+     <title>Atomic queries (APT)</title>

      <para>
       Atomic queries are the query parts which work on one acess point
       only. These consist of <literal>an attribute list</literal>
       followed by a <literal>single term</literal> or a
      <para>
       Atomic queries are the query parts which work on one acess point
       only. These consist of <literal>an attribute list</literal>
       followed by a <literal>single term</literal> or a

-      <literal>quoted term list</literal>.
+      <literal>quoted term list</literal>, and are often called 
+      <emphasis>Attributes-Plus-Terms (APT)</emphasis> queries.

      </para>
      <para>
       Unsupplied non-use attributes type 2-9 are either inherited from
      </para>
      <para>
       Unsupplied non-use attributes type 2-9 are either inherited from

@@ -250,7 +322,9 @@
       See <xref linkend="querymodel-bib1"/> for details. 
      </para>
      
       See <xref linkend="querymodel-bib1"/> for details. 
      </para>
      

-     <table id="querymodel-atomic-queries-table">
+     <table id="querymodel-atomic-queries-table"
+      frame="all" rowsep="1" colsep="1" align="center">
+

       <caption>Atomic queries</caption>
        <!--
        <thead>
       <caption>Atomic queries</caption>
        <!--
        <thead>

@@ -282,7 +356,7 @@
       </screen>
      </para>
      <para>
       </screen>
      </para>
      <para>

-      Equivalent query fully specified:
+      Equivalent query fully specified including all default values:

       <screen>
        Z> find @attrset bib-1 @attr 1=1017 @attr 2=3 @attr 3=3 @attr 4=1 @attr 5=100 @attr 6=1 "information"
       </screen>
       <screen>
        Z> find @attrset bib-1 @attr 1=1017 @attr 2=3 @attr 3=3 @attr 4=1 @attr 5=100 @attr 6=1 "information"
       </screen>

@@ -611,7 +685,7 @@
      In addition, Zebra allows the acess of 
      <emphasis>internal index names</emphasis> and <emphasis>dynamic
      XPath</emphasis> as use attributes. 
      In addition, Zebra allows the acess of 
      <emphasis>internal index names</emphasis> and <emphasis>dynamic
      XPath</emphasis> as use attributes. 

-     See  <xref linkend="querymodel-use-string and  "/>
+     See  <xref linkend="querymodel-use-string"/> and 

      <xref linkend="querymodel-use-xpath"/> for
      alternative acess to the Zebra internal index names and XPath queries.
     </para> 
      <xref linkend="querymodel-use-xpath"/> for
      alternative acess to the Zebra internal index names and XPath queries.
     </para> 

@@ -635,7 +709,9 @@
       side of the relation), e.g., Date-publication &lt;= 1975.
       </para>
 
       side of the relation), e.g., Date-publication &lt;= 1975.
       </para>
 

-     <table id="querymodel-bib1-relation-table">
+     <table id="querymodel-bib1-relation-table"
+      frame="all" rowsep="1" colsep="1" align="center">
+

       <caption>Relation Attributes (type 2)</caption>
       <thead>
         <tr>
       <caption>Relation Attributes (type 2)</caption>
       <thead>
         <tr>

@@ -693,7 +769,7 @@
         <tr>
          <td>AlwaysMatches</td>
          <td>103</td>
         <tr>
          <td>AlwaysMatches</td>
          <td>103</td>

-         <td>supported</td>
+         <td>unsupported</td>

         </tr>
        </tbody>
      </table>
         </tr>
        </tbody>
      </table>

@@ -708,15 +784,14 @@
     <para>
      All ordering operations are based on a lexicographical ordering, 
      <emphasis>expect</emphasis> when the 
     <para>
      All ordering operations are based on a lexicographical ordering, 
      <emphasis>expect</emphasis> when the 

-     structure attribute <literal>numeric (109)</literal> is used. In
+     <literal>structure attribute numeric (109)</literal> is used. In

      this case, ordering is numerical. See 
       <xref linkend="querymodel-bib1-structure"/>.
     </para>
 
      <para>
      Ranked search for <emphasis>information retrieval</emphasis> in
      this case, ordering is numerical. See 
       <xref linkend="querymodel-bib1-structure"/>.
     </para>
 
      <para>
      Ranked search for <emphasis>information retrieval</emphasis> in

-     the title-register
-     (see <xref linkend="administration-ranking"/> for the glory details):
+     the title-register:

      <screen>
       Z> find @attr 1=4 @attr 2=102 "information retrieval"
      </screen>
      <screen>
       Z> find @attr 1=4 @attr 2=102 "information retrieval"
      </screen>

@@ -731,7 +806,9 @@
       within the field or subfield in which it appears.
      </para>
 
       within the field or subfield in which it appears.
      </para>
 

-     <table id="querymodel-bib1-position-table">
+     <table id="querymodel-bib1-position-table"
+      frame="all" rowsep="1" colsep="1" align="center">
+

       <caption>Position Attributes (type 3)</caption>
       <thead>
         <tr>
       <caption>Position Attributes (type 3)</caption>
       <thead>
         <tr>

@@ -786,7 +863,9 @@
       The default configuration is summerized in this table.
      </para>
 
       The default configuration is summerized in this table.
      </para>
 

-     <table id="querymodel-bib1-structure-table">
+     <table id="querymodel-bib1-structure-table"
+      frame="all" rowsep="1" colsep="1" align="center">
+

       <caption>Structure Attributes (type 4)</caption>
       <thead>
         <tr>
       <caption>Structure Attributes (type 4)</caption>
       <thead>
         <tr>

@@ -909,7 +988,9 @@
       document hit set of a search query.
      </para>
 
       document hit set of a search query.
      </para>
 

-     <table id="querymodel-bib1-truncation-table">
+     <table id="querymodel-bib1-truncation-table"
+      frame="all" rowsep="1" colsep="1" align="center">
+

       <caption>Truncation Attributes (type 5)</caption>
       <thead>
         <tr>
       <caption>Truncation Attributes (type 5)</caption>
       <thead>
         <tr>

@@ -1006,7 +1087,9 @@
      set used in a <literal>search</literal> operation query.
     </para>
 
      set used in a <literal>search</literal> operation query.
     </para>
 

-     <table id="querymodel-zebra-attr-search-table">
+     <table id="querymodel-zebra-attr-search-table"
+      frame="all" rowsep="1" colsep="1" align="center">
+

       <caption>Zebra Search Attribute Extentions</caption>
        <thead>
         <tr>
       <caption>Zebra Search Attribute Extentions</caption>
        <thead>
         <tr>

@@ -1159,7 +1242,8 @@
      <title>Zebra Extention Term Reference Attribute (type 10)</title>
     </sect3>
     <para>
      <title>Zebra Extention Term Reference Attribute (type 10)</title>
     </sect3>
     <para>

-     Zebra supports the searchResult-1 facility. If attribute 10 is
+     Zebra supports the <literal>searchResult-1</literal> facility. 
+     If the <literal>Term Reference Attribute (type 10)</literal> is

      given, that specifies a subqueryId value returned as part of the
      search result. It is a way for a client to name an APT part of a
      query. 
      given, that specifies a subqueryId value returned as part of the
      search result. It is a way for a client to name an APT part of a
      query. 

@@ -1185,36 +1269,42 @@
      recognized regardless of attribute 
      set used in a <literal>scan</literal> operation query.
     </para>
      recognized regardless of attribute 
      set used in a <literal>scan</literal> operation query.
     </para>

-     <table id="querymodel-zebra-attr-scan-table">
+     <table id="querymodel-zebra-attr-scan-table"
+      frame="all" rowsep="1" colsep="1" align="center">
+

       <caption>Zebra Scan Attribute Extentions</caption>
        <thead>
         <tr>
       <caption>Zebra Scan Attribute Extentions</caption>
        <thead>
         <tr>

-         <td><emphasis>Name and Type</emphasis></td>
+         <td>Name</td>
+         <td>Type</td>

          <td>Operation</td>
          <td>Zebra version</td>
         </tr>
       </thead>
        <tbody>
         <tr>
          <td>Operation</td>
          <td>Zebra version</td>
         </tr>
       </thead>
        <tbody>
         <tr>

-         <td><emphasis>Result Set Narrow (type 8)</emphasis></td>
+         <td>Result Set Narrow</td>
+         <td>8</td>

          <td>scan</td>
          <td>1.3</td>
         </tr>
         <tr>
          <td>scan</td>
          <td>1.3</td>
         </tr>
         <tr>

-         <td><emphasis>Approximative Limit (type 9)</emphasis></td>
+         <td>Approximative Limit</td>
+         <td>9</td>

          <td>scan</td>
          <td>1.4</td>
         </tr>
        </tbody>
       </table>      
 
          <td>scan</td>
          <td>1.4</td>
         </tr>
        </tbody>
       </table>      
 

-    <sect3 id="querymodel-zebra-attr-xyz">
+    <sect3 id="querymodel-zebra-attr-narrow">

      <title>Zebra Extention Result Set Narrow (type 8)</title>
     </sect3>
     <para>
      <title>Zebra Extention Result Set Narrow (type 8)</title>
     </sect3>
     <para>

-     If attribute 8 is given for scan, the value is the name of a
-     result set. Each hit count in scan is @and'ed with the result set
-     given. 
+     If attribute <literal>Result Set Narrow (type 8)</literal> 
+     is given for <literal>scan</literal>, the value is the name of a
+     result set. Each hit count in <literal>scan</literal> is 
+     <literal>@and</literal>'ed with the result set given. 

     </para>
     <!--
     <para>
     </para>
     <!--
     <para>

@@ -1226,12 +1316,14 @@
      Experimental and buggy. Definitely not to be used in production code.
     </warning>
 
      Experimental and buggy. Definitely not to be used in production code.
     </warning>
 

-    <sect3 id="querymodel-zebra-attr-xyz">
+    <sect3 id="querymodel-zebra-attr-approx">

      <title>Zebra Extention Approximative Limit (type 9)</title>
     </sect3>
     <para>
      <title>Zebra Extention Approximative Limit (type 9)</title>
     </sect3>
     <para>

-     The approximative limit (as for search) is a way to enable approx
-     hit counts for scan hit counts. 
+     The <literal>Zebra Extention Approximative Limit (type
+      9)</literal> is a way to enable approx
+     hit counts for <literal>scan</literal> hit counts, in the same
+     way as for <literal>search</literal> hit counts. 

     </para>
     <!--
     <para>
     </para>
     <!--
     <para>

@@ -1434,7 +1526,9 @@
      Both query types follow the same syntax with the operands:
     </para>
 
      Both query types follow the same syntax with the operands:
     </para>
 

-     <table id="querymodel-regular-operands-table">
+     <table id="querymodel-regular-operands-table"
+      frame="all" rowsep="1" colsep="1" align="center">
+

       <caption>Regular Expression Operands</caption>
        <!--
        <thead>
       <caption>Regular Expression Operands</caption>
        <!--
        <thead>

@@ -1443,15 +1537,15 @@
        -->
        <tbody>
         <tr>
        -->
        <tbody>
         <tr>

-         <td><emphasis>x</emphasis></td>
-         <td>Matches the character <emphasis>x</emphasis>.</td>
+         <td><literal>x</literal></td>
+         <td>Matches the character <literal>x</literal>.</td>

         </tr>
         <tr>
         </tr>
         <tr>

-         <td><emphasis>.</emphasis></td>
+         <td><literal>.</literal></td>

          <td>Matches any character.</td>
         </tr>
         <tr>
          <td>Matches any character.</td>
         </tr>
         <tr>

-         <td><emphasis>[ .. ]</emphasis></td>
+         <td><literal>[ .. ]</literal></td>

          <td>Matches the set of characters specified;
          such as <literal>[abc]</literal> or <literal>[a-c]</literal>.</td>
         </tr>
          <td>Matches the set of characters specified;
          such as <literal>[abc]</literal> or <literal>[a-c]</literal>.</td>
         </tr>

@@ -1462,8 +1556,8 @@
      The above operands can be combined with the following operators:
     </para>
 
      The above operands can be combined with the following operators:
     </para>
 

-    
-     <table id="querymodel-regular-operators-table">
+     <table id="querymodel-regular-operators-table"
+      frame="all" rowsep="1" colsep="1" align="center">

       <caption>Regular Expression Operators</caption>
        <!--
        <thead>
       <caption>Regular Expression Operators</caption>
        <!--
        <thead>

@@ -1472,39 +1566,39 @@
        -->
        <tbody>
         <tr>
        -->
        <tbody>
         <tr>

-         <td><emphasis>x*</emphasis></td>
-         <td>Matches <emphasis>x</emphasis> zero or more times. 
+         <td><literal>x*</literal></td>
+         <td>Matches <literal>x</literal> zero or more times. 

           Priority: high.</td>
         </tr>
         <tr>
           Priority: high.</td>
         </tr>
         <tr>

-         <td><emphasis>x+</emphasis></td>
-         <td>Matches <emphasis>x</emphasis> one or more times. 
+         <td><literal>x+</literal></td>
+         <td>Matches <literal>x</literal> one or more times. 

           Priority: high.</td>
         </tr>
         <tr>
           Priority: high.</td>
         </tr>
         <tr>

-         <td><emphasis>x?</emphasis></td>
-         <td> Matches <emphasis>x</emphasis> zero or once. 
+         <td><literal>x?</literal></td>
+         <td> Matches <literal>x</literal> zero or once. 

           Priority: high.</td>
         </tr>
         <tr>
           Priority: high.</td>
         </tr>
         <tr>

-         <td><emphasis>xy</emphasis></td>
-         <td> Matches <emphasis>x</emphasis>, then <emphasis>y</emphasis>.
+         <td><literal>xy</literal></td>
+         <td> Matches <literal>x</literal>, then <literal>y</literal>.

          Priority: medium.</td>
         </tr>
         <tr>
          Priority: medium.</td>
         </tr>
         <tr>

-         <td><emphasis>x|y</emphasis></td>
-         <td> Matches either <emphasis>x</emphasis> or <emphasis>y</emphasis>.
+         <td><literal>x|y</literal></td>
+         <td> Matches either <literal>x</literal> or <literal>y</literal>.

          Priority: low.</td>
         </tr>
         <tr>
          Priority: low.</td>
         </tr>
         <tr>

-         <td><emphasis>( )</emphasis></td>
+         <td><literal>( )</literal></td>

          <td>The order of evaluation may be changed by using parentheses.</td>
         </tr>
        </tbody>
       </table>      
          <td>The order of evaluation may be changed by using parentheses.</td>
         </tr>
        </tbody>
       </table>      

-    
+

     <para>
     <para>

-     If the first character of the <emphasis>Regxp-2</emphasis> query
+     If the first character of the <literal>Regxp-2</literal> query

      is a plus character (<literal>+</literal>) it marks the
      beginning of a section with non-standard specifiers.
      The next plus character marks the end of the section.
      is a plus character (<literal>+</literal>) it marks the
      beginning of a section with non-standard specifiers.
      The next plus character marks the end of the section.

@@ -1528,8 +1622,7 @@
 
     <para>
      Combinations with other attributes are possible. For example, a
 
     <para>
      Combinations with other attributes are possible. For example, a

-     ranked search with a regular expression 
-     (see <xref linkend="administration-ranking"/> for the glory details):
+     ranked search with a regular expression:

      <screen>
       Z> find @attr 1=4 @attr 5=102 @attr 2=102 "informat.* retrieval"
      </screen>
      <screen>
       Z> find @attr 1=4 @attr 5=102 @attr 2=102 "informat.* retrieval"
      </screen>

@@ -1544,7 +1637,7 @@
     process input records.
     Two basic types of processing are available - raw text and structured
     data. Raw text is just that, and it is selected by providing the
     process input records.
     Two basic types of processing are available - raw text and structured
     data. Raw text is just that, and it is selected by providing the

-    argument <emphasis>text</emphasis> to Zebra. Structured records are
+    argument <literal>text</literal> to Zebra. Structured records are

     all handled internally using the basic mechanisms described in the
     subsequent sections.
     Zebra can read structured records in many different formats.
     all handled internally using the basic mechanisms described in the
     subsequent sections.
     Zebra can read structured records in many different formats.