diff --git a/doc/src/sgml/ref/create_function.sgml b/doc/src/sgml/ref/create_function.sgml
new file mode 100644
index 81278bb..b61b978
*** a/doc/src/sgml/ref/create_function.sgml
--- b/doc/src/sgml/ref/create_function.sgml
*************** CREATE [ OR REPLACE ] FUNCTION
*** 252,261 ****
       <listitem>
        <para>
         The name of the language that the function is implemented in.
!        Can be <literal>SQL</literal>, <literal>C</literal>,
         <literal>internal</literal>, or the name of a user-defined
!        procedural language.  For backward compatibility,
!        the name can be enclosed by single quotes.
        </para>
       </listitem>
      </varlistentry>
--- 252,261 ----
       <listitem>
        <para>
         The name of the language that the function is implemented in.
!        It can be <literal>sql</literal>, <literal>c</literal>,
         <literal>internal</literal>, or the name of a user-defined
!        procedural language, e.g. <literal>plpgsql</literal>.  Enclosing the
!        name in single quotes is deprecated and requires matching case.
        </para>
       </listitem>
      </varlistentry>