creating an extension, but not during extension updates
        (since that might override user-added comments).  Alternatively,
        the extension's comment can be set by writing
        a <xref linkend="sql-comment"/> command in the script file.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry id="extend-extensions-files-encoding">
      <term><varname>encoding</varname> (<type>string</type>)</term>
      <listitem>
       <para>
        The character set encoding used by the script file(s).  This should
        be specified if the script files contain any non-ASCII characters.
        Otherwise the files will be assumed to be in the database encoding.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry id="extend-extensions-files-module-pathname">
      <term><varname>module_pathname</varname> (<type>string</type>)</term>
      <listitem>
       <para>
        The value of this parameter will be substituted for each occurrence
        of <literal>MODULE_PATHNAME</literal> in the script file(s).  If it is not
        set, no substitution is made.  Typically, this is set to just
        <literal><replaceable>shared_library_name</replaceable></literal> and
        then <literal>MODULE_PATHNAME</literal> is used in <command>CREATE
        FUNCTION</command> commands for C-language functions, so that the script
        files do not need to hard-wire the name of the shared library.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry id="extend-extensions-files-requires">
      <term><varname>requires</varname> (<type>string</type>)</term>
      <listitem>
       <para>
        A list of names of extensions that this extension depends on,
        for example <literal>requires = 'foo, bar'</literal>.  Those
        extensions must be installed before this one can be installed.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry id="extend-extensions-files-no-relocate">
      <term><varname>no_relocate</varname> (<type>string</type>)</term>
      <listitem>
       <para>
        A list of names of extensions that this extension depends on that
        should be barred from changing their schemas via <command>ALTER
        EXTENSION ... SET SCHEMA</command>.
        This is needed if this extension's script references the name
        of a required extension's schema (using
        the <literal>@extschema:<replaceable>name</replaceable>@</literal>
        syntax) in a way that cannot track renames.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry id="extend-extensions-files-superuser">
      <term><varname>superuser</varname> (<type>boolean</type>)</term>
      <listitem>
       <para>
        If this parameter is <literal>true</literal> (which is the default),
        only superusers can create the extension or update it to a new
        version (but see also <varname>trusted</varname>, below).
        If it is set to <literal>false</literal>, just the privileges
        required to execute the commands in the installation or update script
        are required.
        This should normally be set to <literal>true</literal> if any of the
        script commands require superuser privileges.  (Such commands would
        fail anyway, but it's more user-friendly to give the error up front.)
       </para>
      </listitem>
     </varlistentry>

     <varlistentry id="extend-extensions-files-trusted">
      <term><varname>trusted</varname> (<type>boolean</type>)</term>
      <listitem>
       <para>
        This parameter, if set to <literal>true</literal> (which is not the
        default), allows some non-superusers to install an extension that
        has <varname>superuser</varname> set to <literal>true</literal>.
        Specifically, installation will be permitted for anyone who has
        <literal>CREATE</literal> privilege on the current database.
        When the user executing <command>CREATE EXTENSION</command>