added business category oid
diff --git a/docs/x509/reference.rst b/docs/x509/reference.rst
index f4b372e..91c5344 100644
--- a/docs/x509/reference.rst
+++ b/docs/x509/reference.rst
@@ -1863,6 +1863,10 @@
 
         Corresponds to the dotted string ``"1.3.6.1.4.1.311.60.2.1.2"``.
 
+    .. attribute:: BUSINESS_CATEGORY
+
+        Corresponds to the dotted string ``"2.5.4.15"``.
+
 
 .. class:: SignatureAlgorithmOID