Document the vector
diff --git a/docs/development/test-vectors.rst b/docs/development/test-vectors.rst
index ad945f2..d62fb93 100644
--- a/docs/development/test-vectors.rst
+++ b/docs/development/test-vectors.rst
@@ -110,6 +110,9 @@
containing a SAN extension with an ``ediPartyName`` general name.
* ``san_x400address.der`` - A DSA certificate from a `Mozilla bug`_ containing
a SAN extension with an ``x400Address`` general name.
+* ``department-of-state-root.pem`` - The intermediary CA for the Department of
+ State, issued by the United States Federal Government's Common Policy CA.
+ Notably has a ``critical`` policy constraints extensions.
Custom X.509 Vectors
~~~~~~~~~~~~~~~~~~~~