diff --git a/Documentation/git-get-tar-commit-id.txt b/Documentation/git-get-tar-commit-id.txt
index f9c4140..0eb5e28 100644
--- a/Documentation/git-get-tar-commit-id.txt
+++ b/Documentation/git-get-tar-commit-id.txt
@@ -3,25 +3,24 @@
 
 NAME
 ----
-git-get-tar-commit-id - Some git command not yet documented.
+git-get-tar-commit-id - Extract commit ID from an archive created using git-tar-tree.
 
 
 SYNOPSIS
 --------
-'git-get-tar-commit-id' [ --option ] <args>...
+'git-get-tar-commit-id' < <tarfile>
+
 
 DESCRIPTION
 -----------
-Does something not yet documented.
+Acts as a filter, extracting the commit ID stored in archives created by
+git-tar-tree.  It reads only the first 1024 bytes of input, thus its
+runtime is not influenced by the size of <tarfile> very much.
 
-
-OPTIONS
--------
---option::
-	Some option not yet documented.
-
-<args>...::
-	Some argument not yet documented.
+If no commit ID is found, git-get-tar-commit-id quietly exists with a
+return code of 1.  This can happen if <tarfile> had not been created
+using git-tar-tree or if the first parameter of git-tar-tree had been
+a tree ID instead of a commit ID or tag.
 
 
 Author
diff --git a/Documentation/git.txt b/Documentation/git.txt
index 0bcd990..b10edff 100644
--- a/Documentation/git.txt
+++ b/Documentation/git.txt
@@ -319,6 +319,8 @@
 link:git-send-email-script.html[git-send-email]::
 	Send patch e-mails out of "format-patch --mbox" output.
 
+link:git-get-tar-commit-id.html[git-get-tar-commit-id]::
+	Extract commit ID from an archive created using git-tar-tree.
 
 Commands not yet documented
 ---------------------------
@@ -338,9 +340,6 @@
 link:git-format-patch-script.html[git-format-patch-script]::
 	git-format-patch-script.
 
-link:git-get-tar-commit-id.html[git-get-tar-commit-id]::
-	git-get-tar-commit-id.
-
 link:git-request-pull-script.html[git-request-pull-script]::
 	git-request-pull-script.
 
diff --git a/get-tar-commit-id.c b/get-tar-commit-id.c
index a1a17e5..4166290 100644
--- a/get-tar-commit-id.c
+++ b/get-tar-commit-id.c
@@ -1,3 +1,6 @@
+/*
+ * Copyright (C) 2005 Rene Scharfe
+ */
 #include <stdio.h>
 #include <string.h>
 #include <unistd.h>