diff --git a/doc/src/sgml/user-manag.sgml b/doc/src/sgml/user-manag.sgml
index 93978e550e9..d99dcb2017f 100644
--- a/doc/src/sgml/user-manag.sgml
+++ b/doc/src/sgml/user-manag.sgml
@@ -88,9 +88,13 @@ dropuser <replaceable>name</replaceable>
 
   <para>
    To determine the set of existing roles, examine the <structname>pg_roles</structname>
-   system catalog, for example
+   system catalog, for example:
 <synopsis>
 SELECT rolname FROM pg_roles;
+</synopsis>
+   or to see just those capable of logging in:
+<synopsis>
+SELECT rolname FROM pg_roles WHERE rolcanlogin;
 </synopsis>
    The <xref linkend="app-psql"/> program's <literal>\du</literal> meta-command
    is also useful for listing the existing roles.
@@ -98,11 +102,12 @@ SELECT rolname FROM pg_roles;
 
   <para>
    In order to bootstrap the database system, a freshly initialized
-   system always contains one predefined role. This role is always
-   a <quote>superuser</quote>, and by default (unless altered when running
-   <command>initdb</command>) it will have the same name as the
-   operating system user that initialized the database
-   cluster. Customarily, this role will be named
+   system always contains one predefined login-capable role. This role
+   is always a <quote>superuser</quote>, and by default it will have
+   the same name as the operating system user that initialized the
+   database cluster, unless another name is specified while
+   running <command>initdb</command>.
+   It is common, but not required, to arrange for this role to be named
    <literal>postgres</literal>. In order to create more roles you
    first have to connect as this initial role.
   </para>