diff --git a/doc/src/sgml/ref/create_index.sgml b/doc/src/sgml/ref/create_index.sgml
new file mode 100644
index 2ab6470..17b433a
*** a/doc/src/sgml/ref/create_index.sgml
--- b/doc/src/sgml/ref/create_index.sgml
*************** CREATE [ UNIQUE ] INDEX [ CONCURRENTLY ]
*** 394,408 ****
     </para>
  
     <para>
!     In a concurrent index build, the index is actually entered into the
!     system catalogs in one transaction, then the two table scans occur in a
!     second and third transaction.  All active transactions at the time the
!     second table scan starts, not just ones that already involve the table,
!     have the potential to block the concurrent index creation until they
!     finish.  When checking for transactions that could still use the original
!     index, concurrent index creation advances through potentially interfering
!     older transactions one at a time, obtaining shared locks on their virtual
!     transaction identifiers to wait for them to complete.
     </para>
  
     <para>
--- 394,407 ----
     </para>
  
     <para>
!     In a concurrent index build, the index is actually entered into
!     the system catalogs in one transaction, then two table scans occur in
!     two more transactions.  Any transaction active when the second table
!     scan starts can block concurrent index creation until it completes,
!     even transactions that only reference the table after the second table
!     scan starts.   Concurrent index creation serially waits for each old
!     transaction to complete using the method outlined in section <xref
!     linkend="view-pg-locks">.
     </para>
  
     <para>