diff --git a/README.md b/README.md
index cb039c5..3d9ad4c 100644
--- a/README.md
+++ b/README.md
@@ -27,12 +27,11 @@ pzztool.py -bp source_folder optional_dest_folder
 ### Extracted files format
 Every file extracted has a name using the format :
 
-AAAB_CD.E
+AAAB_C.D
 - **AAA** is the 3 digits index of the file in the PZZ starting at 000.
 - **B** describe the compression state of the file when packed in the PZZ. If compressed it's **C** and if not it's **U**.
 - **C** is the name of the PZZ.
-- **D** describe the actual compression state of the file. It's **\_compressed** if the file is compressed and nothing if the file is uncompressed.
-- **E** is the extension of the file. By default it is **.dat**
+- **D** is the extension of the file. If the file is compressed it's **.pzzp** and if the file is uncompressed by default it's **.dat**
 
 For example file **012C_cmn_data.dat** describe :
 - the 13th file off the pzz,