diff --git a/Documentation/git-checkout.txt b/Documentation/git-checkout.txt
index 37c1810e3fc8424868333a22094107e99764fc37..a3a87fa7fd29973e15afb93382646ae6f89d0f61 100644
--- a/Documentation/git-checkout.txt
+++ b/Documentation/git-checkout.txt
@@ -136,6 +136,10 @@ edits from your current working tree.
 As a special case, the `"@\{-N\}"` syntax for the N-th last branch
 checks out the branch (instead of detaching).  You may also specify
 `-` which is synonymous with `"@\{-1\}"`.
++
+As a further special case, you may use `"A...B"` as a shortcut for the
+merge base of `A` and `B` if there is exactly one merge base. You can
+leave out at most one of `A` and `B`, in which case it defaults to `HEAD`.
 
 <new_branch>::
 	Name for the new branch.
diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
index 5863decdc9f96669e839b3e16cc265ddb699fce7..50ba2e469f48f1bc16c3f6e3b6f6451a9e29637a 100644
--- a/Documentation/git-rebase.txt
+++ b/Documentation/git-rebase.txt
@@ -206,6 +206,10 @@ OPTIONS
 	--onto option is not specified, the starting point is
 	<upstream>.  May be any valid commit, and not just an
 	existing branch name.
++
+As a special case, you may use "A...B" as a shortcut for the
+merge base of A and B if there is exactly one merge base. You can
+leave out at most one of A and B, in which case it defaults to HEAD.
 
 <upstream>::
 	Upstream branch to compare against.  May be any valid commit,