diff --git a/README.md b/README.md
index 6f503e6..cafb6d4 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,19 @@
 wbackup
 ===============
 
-Calclate 32bit checksum and SHA256 hash.
-this file exist in duplicate check database.
-if not exist then comppress source file and export binary database.
-add sourcefile database.
+1. Calclate 32bit checksum and SHA256 hash.
+* this file exist in duplicate check database.
+* if not exist then comppress source file and export binary database.
+* add sourcefile database.
+* remove oldest files.
+* remove archive flags.
+
+## duplicate check database
+32bit checksum
+SHA-256 hash
+binary data stream id
+
+## binary data stream
+binary data stream id
+32bit HEX
+FFFF-FFFF-FFFF-FFFF-FFFFFFFF.gzip