rename tbs_certificate to tbs_certificate_bytes, add a comment
diff --git a/src/cryptography/x509/base.py b/src/cryptography/x509/base.py
index 53893a1..ad561b9 100644
--- a/src/cryptography/x509/base.py
+++ b/src/cryptography/x509/base.py
@@ -124,7 +124,7 @@
         """
 
     @abc.abstractproperty
-    def tbs_certificate(self):
+    def tbs_certificate_bytes(self):
         """
         Returns the tbsCertificate payload bytes as defined in RFC 5280.
         """