doc: more replacement of <literal> with something better

Reported-by: Alexander Law

Author: Alexander Law

Backpatch-through: 9.6

doc/src/sgml/config.sgml

@@ -1227,8 +1227,8 @@ include_dir 'conf.d'
        </para>
 
        <para>
-        If this is on, you should create users as <literal>username@dbname</>.
-        When <literal>username</> is passed by a connecting client,
+        If this is on, you should create users as <replaceable>username@dbname</>.
+        When <replaceable>username</> is passed by a connecting client,
         <literal>@</> and the database name are appended to the user
         name and that database-specific user name is looked up by the
         server. Note that when you create users with names containing

doc/src/sgml/func.sgml

@@ -13800,7 +13800,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
       <entry>No</entry>
       <entry>
        multiple continuous percentile: returns an array of results matching
-       the shape of the <literal>fractions</literal> parameter, with each
+       the shape of the <replaceable>fractions</replaceable> parameter, with each
        non-null element replaced by the value corresponding to that percentile
       </entry>
      </row>
@@ -13845,7 +13845,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
       <entry>No</entry>
       <entry>
        multiple discrete percentile: returns an array of results matching the
-       shape of the <literal>fractions</literal> parameter, with each non-null
+       shape of the <replaceable>fractions</replaceable> parameter, with each non-null
        element replaced by the input value corresponding to that percentile
       </entry>
      </row>
@@ -16850,7 +16850,7 @@ SELECT pg_type_is_visible('myschema.widget'::regtype);
   <para>
    <function>pg_options_to_table</function> returns the set of storage
    option name/value pairs
-   (<literal>option_name</>/<literal>option_value</>) when passed
+   (<replaceable>option_name</>/<replaceable>option_value</>) when passed
    <structname>pg_class</>.<structfield>reloptions</> or
    <structname>pg_attribute</>.<structfield>attoptions</>.
   </para>

doc/src/sgml/ref/create_sequence.sgml

@@ -349,7 +349,7 @@ END;
    <itemizedlist>
     <listitem>
      <para>
-      The standard's <literal>AS &lt;data type&gt;</literal> expression is not
+      The standard's <literal>AS <replaceable>data_type</></literal> expression is not
       supported.
      </para>
     </listitem>

doc/src/sgml/ref/set_role.sgml

@@ -127,7 +127,7 @@ SELECT SESSION_USER, CURRENT_USER;
 
   <para>
    <productname>PostgreSQL</productname>
-   allows identifier syntax (<literal>"rolename"</literal>), while
+   allows identifier syntax (<literal>"<replaceable>rolename</>"</literal>), while
    the SQL standard requires the role name to be written as a string
    literal.  SQL does not allow this command during a transaction;
    <productname>PostgreSQL</productname> does not make this

doc/src/sgml/ref/set_session_auth.sgml

@@ -101,7 +101,7 @@ SELECT SESSION_USER, CURRENT_USER;
    The SQL standard allows some other expressions to appear in place
    of the literal <replaceable>user_name</replaceable>, but these options
    are not important in practice.  <productname>PostgreSQL</productname>
-   allows identifier syntax (<literal>"username"</literal>), which SQL
+   allows identifier syntax (<literal>"<replaceable>username</>"</literal>), which SQL
    does not.  SQL does not allow this command during a transaction;
    <productname>PostgreSQL</productname> does not make this
    restriction because there is no reason to.

doc/src/sgml/textsearch.sgml

@@ -3622,10 +3622,10 @@ SELECT plainto_tsquery('supernovae stars');
   </para>
 
   <para>
-   The optional parameter <literal>PATTERN</literal> can be the name of
+   The optional parameter <replaceable>PATTERN</replaceable> can be the name of
    a text search object, optionally schema-qualified.  If
-   <literal>PATTERN</literal> is omitted then information about all
-   visible objects will be displayed.  <literal>PATTERN</literal> can be a
+   <replaceable>PATTERN</replaceable> is omitted then information about all
+   visible objects will be displayed.  <replaceable>PATTERN</replaceable> can be a
    regular expression and can provide <emphasis>separate</emphasis> patterns
    for the schema and object names.  The following examples illustrate this:
 

doc/src/sgml/xfunc.sgml

@@ -204,8 +204,8 @@ SELECT clean_emp();
 
     <para>
      If an argument is of a composite type, then the dot notation,
-     e.g., <literal>argname.fieldname</literal> or
-     <literal>$1.fieldname</literal>, can be used to access attributes of the
+     e.g., <literal><replaceable>argname</>.<replaceable>fieldname</></literal> or
+     <literal>$1.<replaceable>fieldname</></literal>, can be used to access attributes of the
      argument.  Again, you might need to qualify the argument's name with the
      function name to make the form with an argument name unambiguous.
     </para>
@@ -527,7 +527,8 @@ LINE 1: SELECT new_emp().name;
      Another option is to use
      functional notation for extracting an attribute.  The  simple  way
      to explain this is that we can use the
-     notations <literal>attribute(table)</>  and  <literal>table.attribute</>
+     notations <literal><replaceable>attribute</>(<replaceable>table</>)</>
+     and  <literal><replaceable>table</>.<replaceable>attribute</></>
      interchangeably.
 
 <screen>
@@ -1305,12 +1306,15 @@ CREATE FUNCTION test(smallint, double precision) RETURNS ...
    <para>
     A function that takes a single argument of a composite type should
     generally not have the same name as any attribute (field) of that type.
-    Recall that <literal>attribute(table)</literal> is considered equivalent
-    to <literal>table.attribute</literal>.  In the case that there is an
+    Recall that <literal><replaceable>attribute</>(<replaceable>table</>)</literal>
+    is considered equivalent
+    to <literal><replaceable>table</>.<replaceable>attribute</></literal>.
+    In the case that there is an
     ambiguity between a function on a composite type and an attribute of
     the composite type, the attribute will always be used.  It is possible
     to override that choice by schema-qualifying the function name
-    (that is, <literal>schema.func(table)</literal>) but it's better to
+    (that is, <literal><replaceable>schema</>.<replaceable>func</>(<replaceable>table</>)
+    </literal>) but it's better to
     avoid the problem by not choosing conflicting names.
    </para>
 
@@ -2818,7 +2822,7 @@ HeapTuple heap_form_tuple(TupleDesc tupdesc, Datum *values, bool *isnull)
 HeapTuple BuildTupleFromCStrings(AttInMetadata *attinmeta, char **values)
 </programlisting>
      to build a <structname>HeapTuple</> given user data
-     in C string form.  <literal>values</literal> is an array of C strings,
+     in C string form.  <parameter>values</parameter> is an array of C strings,
      one for each attribute of the return row. Each C string should be in
      the form expected by the input function of the attribute data
      type. In order to return a null value for one of the attributes,