diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index d77312600f..2d4ab85d45 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -616,7 +616,7 @@ CREATE TABLE cities (
);
CREATE TABLE capitals (
- state char(2)
+ state char(2) UNIQUE NOT NULL
) INHERITS (cities);
@@ -630,7 +630,8 @@ CREATE TABLE capitals (
text, a native PostgreSQL
type for variable length character strings. The
capitals table has
- an extra column, state, which shows their states. In
+ an additional column, state, which shows its
+ state abbreviation. In
PostgreSQL, a table can inherit from
zero or more other tables.