diff --git a/README b/README
index b6ed22d..0887d44 100644
--- a/README
+++ b/README
@@ -40,6 +40,7 @@ Bugs/Todo
 * (cue/toc) Strings cannot be quoted with single quotes.
 * (toc) Binary CD-TEXT data is parsed, but not saved.
 * (toc) Only a single data file is supported.
+* (cue) CDTEXTFILE (a CDRWIN extension) is not recognized.
 
 License
 -------
diff --git a/docs/formats.txt b/docs/formats.txt
index f21997d..c516020 100644
--- a/docs/formats.txt
+++ b/docs/formats.txt
@@ -53,6 +53,20 @@ CATALOG
 	``catalog_number``
 		an integer consisting of exactly 13 digits.
 
+CDTEXTFILE
+~~~~~~~~~~
+
+:Description: Sets an external file for CD-TEXT data.
+:Section(s): global
+:Format:
+	``CDTEXTFILE <filename>``
+
+	``filename``
+		a string.
+
+The CD-TEXT file contains encoded CD-TEXT data.  The standard extension for
+CD-TEXT files is ``.cdt``.
+
 FILE
 ~~~~