diff --git a/README b/README
index c8150b7..d34b0eb 100644
--- a/README
+++ b/README
@@ -1,62 +1,67 @@
 SWH-loader-dir
 ==============
 
 # TL;DR
 
 WIP -> Main entry point is scratch/walking.py for the moment
 
 
 The Software Heritage Loader Dir is a tool and a library to walk a local
 Directory and inject into the SWH dataset all unknown contained files.
 
 
 
 Git sha1 computation
 --------------------
 
 ### commit/revision
 
 sha1 git commit/revision computation:
 
     commit `size`\0
     tree `sha1-git-tree-and-subtree-in-plain-hex-string`
-    parent `commit-parent`
-    author `author-name` <`author-email`> `author-date-ts` `author-date-offset`
-    committer `committer-name` <`committer-email`> `committer-date-ts` `committer-date-offset`
+    (parent `commit-parent`)
+    author `name` <`email`> `date-ts` `date-offset`
+    committer `name` <`email`> `date-ts` `date-offset`
 
     `commit-message`
 
+
 Notes:
-- no newline
+- () denotes optional entry. Indeed, first commit does not contain any parent commit.
+- empty line at the end of the commit message
+- timestamp example: 1444054085
 - date offset for example: +0200
 
 ### directory/tree
 
 sha1 git directory/tree computation:
 
     tree `tree-size`\0
-    <file-perm> <file-name>\0<file-sha1-in-20-bytes-string>
-    <dir-perm> <dir-name>\0<dir-sha1-in-20-bytes-string>
+    <file-perm> <file-name>\0<file-sha1-in-20-bytes-string>...<dir-perm> <dir-name>\0<dir-sha1-in-20-bytes-string>...
 
 
 Notes:
 - no newline separator between tree entries
-- tree content size is the length of the content
-- What's the entry order? byte order on the filename
-  -> `git mk-tree` does not need to presort the input -> git mktree creates a tree and store in a git file storage -> no go
+- no empty newline at the end of the tree entries
+- tree content header size is the length of the content
+- The tree entries are ordered according to bytes in their <name> properties.
 
-permissions:
+Possible permissions are:
 - 100644 - file
 - 40000  - directory
 - 100755 - executable file
 - 120000 - symbolink link
-- 160000 - git link
+- 160000 - git link (relative to submodule)
 
 ### content/file
 
 sha1 git content computation:
 
     blob `blob-size`\0
     `blob-content`
 
+Notes:
+- no newline at the end of the blob content
+
 Compress with DEFLATE and compute sha1