1 files changed, 17 insertions, 0 deletions
diff --git a/README.md b/README.md
index 6c93395..9062054 100644
--- a/README.md
+++ b/README.md
@@ -33,3 +33,20 @@ A heap page looks like this:
     |   header    |
     |-------------|
 
+BTree File
+==========
+
+BTree Item
+----------
+
+* `bytes[] key`
+* `int pageNo` - the page in the heap that contains the value.
+
+A heap page can contain many items so the heap page has to be scanned.
+
+
+Example BTree page
+------------------
+
+    [1, #], [7, #], [9, #]
+