diff --git a/ChangeLog b/ChangeLog
index 84c59640c..dcbdba5d4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2004-04-29  Werner Lemberg  <wl@gnu.org>
+
+	* docs/formats.txt: Add more information on PFR format.
+
 2004-04-28  Werner Lemberg  <wl@gnu.org>
 
 	* docs/formats.txt: New file.
diff --git a/docs/formats.txt b/docs/formats.txt
index 55caad5e0..b11f6c409 100644
--- a/docs/formats.txt
+++ b/docs/formats.txt
@@ -113,7 +113,9 @@ MAC  ---     PS     TYPE_1  ---        type1    T1_SPEC.pdf
 ---  LZW     PCF    ---     ---        pcf      X11
 
 
----  ---     PFR    ---     ---        pfr      ?
+---  ---     PFR    PFR0    ---        pfr      [2]
+---  ---     PFR    PFR1    ---        ---      (undocumented, proprietary;
+                                                probably never supported)
 
 
 ---  ---     WINFNT ---     ---        winfonts MS Windows 3 Developer's Notes
@@ -122,3 +124,16 @@ MAC  ---     PS     TYPE_1  ---        type1    T1_SPEC.pdf
 
 [1] Support should be rather simple since this is identical to `CFF'
     but in a PS wrapper.
+
+[2] Official PFR specification:
+
+      http://www.bitstream.com/categories/developer/truedoc/pfrspec.html
+      http://www.bitstream.com/categories/developer/truedoc/pfrspec1.2.pdf
+
+    The syntax of the auxiliary data is not defined there, but is partially
+    defined in MHP 1.0.3 (also called ETSI TS 101812 V1.3.1) section 7.4.
+
+      http://www.etsi.org/
+      http://webapp.etsi.org/workprogram/Report_WorkItem.asp?WKI_ID=18799
+
+    (free registration required).