diff --git a/doc/src/sgml/client-auth.sgml b/doc/src/sgml/client-auth.sgml
index 3e7a9efd8cc..dd82e8af0d7 100644
--- a/doc/src/sgml/client-auth.sgml
+++ b/doc/src/sgml/client-auth.sgml
@@ -838,8 +838,9 @@ local   db1,db2,@demodbs  all                                   md5
    the remainder of the field is treated as a regular expression.
    (See <xref linkend="posix-syntax-details"/> for details of
    <productname>PostgreSQL</productname>'s regular expression syntax.)  The regular
-   expression can include a single capture, or parenthesized subexpression,
-   which can then be referenced in the <replaceable>database-username</replaceable>
+   expression can include a single capture, or parenthesized subexpression.
+   The portion of the system user name that matched the capture can then
+   be referenced in the <replaceable>database-username</replaceable>
    field as <literal>\1</literal> (backslash-one).  This allows the mapping of
    multiple user names in a single line, which is particularly useful for
    simple syntax substitutions.  For example, these entries