update comment to include a bit more detail
diff --git a/src/cryptography/hazmat/backends/openssl/backend.py b/src/cryptography/hazmat/backends/openssl/backend.py
index db7022e..775430d 100644
--- a/src/cryptography/hazmat/backends/openssl/backend.py
+++ b/src/cryptography/hazmat/backends/openssl/backend.py
@@ -120,8 +120,8 @@
value = attribute.value.encode('utf8')
obj = _txt2obj_gc(backend, attribute.oid.dotted_string)
if attribute.oid == NameOID.COUNTRY_NAME:
- # Per RFC5280 countryName should be encoded as PrintableString,
- # not UTF8String
+ # Per RFC5280 Appendix A.1 countryName should be encoded as
+ # PrintableString, not UTF8String
type = backend._lib.MBSTRING_ASC
else:
type = backend._lib.MBSTRING_UTF8