diff --git a/doc/src/sgml/ref/alter_table.sgml b/doc/src/sgml/ref/alter_table.sgml
index 8c4d6980fed..a8cbfb5bc68 100644
--- a/doc/src/sgml/ref/alter_table.sgml
+++ b/doc/src/sgml/ref/alter_table.sgml
@@ -1,5 +1,5 @@
@@ -506,6 +506,12 @@ ALTER TABLE distributors ADD PRIMARY KEY (dist_id);
The clauses to rename tables, columns, indexes, and sequences are
PostgreSQL extensions from SQL92.
+
+
+ ALTER TABLE DROP COLUMN> can be used to drop the only column
+ of a table, leaving a zero-column table. This is an extension from SQL92,
+ which disallows zero-column tables.
+
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 6d67f22a6b9..db51a26469f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -1,5 +1,5 @@
@@ -915,6 +915,19 @@ CREATE ASSERTION name CHECK ( condition<
standard.
+
+
+ Zero-column tables
+
+
+ PostgreSQL allows a table of no columns
+ to be created (for example, CREATE TABLE foo();>). This
+ is an extension from the SQL standard, which does not allow zero-column
+ tables. Zero-column tables are not in themselves very useful, but
+ disallowing them creates odd special cases for ALTER TABLE
+ DROP COLUMN>, so it seems cleaner to ignore this spec restriction.
+
+