*** a/doc/src/sgml/ref/pgupgrade.sgml
--- b/doc/src/sgml/ref/pgupgrade.sgml
***************
*** 258,267 **** make prefix=/usr/local/pgsql.new install
  
      <para>
       Initialize the new cluster using <command>initdb</command>.
!      Again, use compatible <command>initdb</command>
!      flags that match the old cluster. Many
!      prebuilt installers do this step automatically. There is no need to
!      start the new cluster.
      </para>
     </step>
  
--- 258,272 ----
  
      <para>
       Initialize the new cluster using <command>initdb</command>.
!      The <literal>--encoding</literal>, <literal>--locale</literal> and
!      <literal>--data-checksums</literal> flags for
!      <command>initdb</command> must match the old cluster.
!      Encoding and locale can be discovered by listing databases
!      in the old cluster and looking at the <literal>template0</literal>
!      database.  Data-checksums can be discovered by running
!      <command>pg_controldata</command> against the old data directory.
!      Many prebuilt installers do this step automatically.  There is no
!      need to start the new cluster.
      </para>
     </step>