diff --git a/src/keri/vc/proving.py b/src/keri/vc/proving.py
index 699b598a..5f92717f 100644
--- a/src/keri/vc/proving.py
+++ b/src/keri/vc/proving.py
@@ -3,7 +3,8 @@
 keri.vc.proving module
 
 """
-from typing import Optional
+
+from typing import Optional, Union
 
 from .. import core
 from .. import help
@@ -17,37 +18,37 @@
 logger = help.ogler.getLogger()
 
 
-def credential(schema,
-               issuer,
-               data,
-               recipient=None,
+def credential(schema:str,
+               issuer:str,
+               data:dict,
+               recipient:Optional[str]=None,
                private:bool=False,
                private_credential_nonce:Optional[str]=None,
                private_subject_nonce:Optional[str]=None,
-               status=None,
-               source=None,
-               rules=None,
-               version=Version,
-               kind=Kinds.json):
+               status:str=None,
+               source:Union[dict, list]=None,
+               rules:Union[dict, list]=None,
+               version:Version=Version,
+               kind:Kinds=Kinds.json):
     """Utility function to create an ACDC. Creates dict SAD for credential from
     parameters and Saidifyies it before creation.
 
     Parameters:
-        schema (SAID): of schema for this credential
+        schema (str): SAID of schema for this credential
         issuer (str): qb64 identifier prefix of the issuer
-        status (str): qb64 said of the credential registry
-        recipient (Option[str|None]): qb64 identifier prefix of the recipient
         data (dict): of the values being assigned to the subject of this credential
+        recipient (Optional[str]): qb64 identifier prefix of the recipient
         private (bool): apply nonce used for privacy preserving ACDC
         private_credential_nonce (Optional[str]): nonce used for privacy vc
         private_subject_nonce (Optional[str]): nonce used for subject
-        source (dict | list): of source credentials to which this credential is chained
-        rules (dict | list): ACDC rules section for credential
+        status (str): qb64 said of the credential registry
+        source (Union[dict, list]): of source credentials to which this credential is chained
+        rules (Union[dict, list]): ACDC rules section for credential
         version (Version): version instance
-        kind (Serials): serialization kind
+        kind (Kinds): serialization kind
 
     Returns:
-        SerderACDC: credential instance
+        serdering.SerderACDC: credential instance
 
     """
     vs = versify(protocol=coring.Protocols.acdc, version=version, kind=kind, size=0)