diff --git a/Documentation/git-branch.txt b/Documentation/git-branch.txt
index 72fb2f89b4..0b37e2bfc8 100644
--- a/Documentation/git-branch.txt
+++ b/Documentation/git-branch.txt
@@ -43,6 +43,9 @@ OPTIONS
 
 <branchname>::
 	The name of the branch to create or delete.
+	The new branch name must pass all checks defined by
+	gitlink:git-check-ref-format[1].  Some of these checks
+	may restrict the characters allowed in a branch name.
 
 <start-point>::
 	The new branch will be created with a HEAD equal to this.  It may
diff --git a/Documentation/git-checkout.txt b/Documentation/git-checkout.txt
index 095128906a..d82efc00d4 100644
--- a/Documentation/git-checkout.txt
+++ b/Documentation/git-checkout.txt
@@ -35,7 +35,10 @@ OPTIONS
 	Force a re-read of everything.
 
 -b::
-	Create a new branch and start it at <branch>.
+	Create a new branch named <new_branch> and start it at
+	<branch>.  The new branch name must pass all checks defined
+	by gitlink:git-check-ref-format[1].  Some of these checks
+	may restrict the characters allowed in a branch name.
 
 -m::
 	If you have local modifications to one or more files that