diff --git a/doc/src/sgml/file-fdw.sgml b/doc/src/sgml/file-fdw.sgml
index 8c52761..d7e508d 100644
--- a/doc/src/sgml/file-fdw.sgml
+++ b/doc/src/sgml/file-fdw.sgml
@@ -112,6 +112,10 @@
  </variablelist>
 
  <para>
+  Note that, unlike <command>COPY</>, an option's value is always required here.
+ </para>
+
+ <para>
   A column of a foreign table created using this wrapper can have the
   following options:
  </para>