clarify there is no polymorphism

Co-authored-by: Oliver Terbu <[email protected]>

openid-4-verifiable-credential-issuance-1_0.md

@@ -448,7 +448,7 @@ Note: Applications MAY combine authorization details of type `openid_credential`
 
 In addition to a mechanism defined in (#credential-authz-request), Credential Issuers MAY support requesting authorization to issue a Credential using OAuth 2.0 scope parameter.
 
-When the Wallet does not know which scope value to use to request issuance of a certain Credential, it can discover it using the `scope` Credential Issuer metadata parameter defined in (#credential-issuer-parameters). When the flow starts with a Credential Offer, the Wallet can use the `credentials_configurations_offered` parameter values to identify object(s) in the `credential_configurations_supported` map in the Credential Issuer metadata parameter and use `scope` parameter value from that object.
+When the Wallet does not know which scope value to use to request issuance of a certain Credential, it can discover it using the `scope` Credential Issuer metadata parameter defined in (#credential-issuer-parameters). When the flow starts with a Credential Offer, the Wallet can use the `credential_configurations_offered` parameter values to identify object(s) in the `credential_configurations_supported` map in the Credential Issuer metadata parameter and use `scope` parameter value from that object.
 
 The Wallet can discover the scope values using other options such as normative text in a profile of this specification that defines scope values along with a description of their semantics.
 
@@ -609,7 +609,7 @@ In addition to the response parameters defined in [@!RFC6749], the AS MAY return
 * `c_nonce`: OPTIONAL. String containing a nonce to be used when creating a proof of possession of the key proof (see (#credential_request)). When received, the Wallet MUST use this nonce value for its subsequent requests until the Credential Issuer provides a fresh nonce.
 * `c_nonce_expires_in`: OPTIONAL. Number denoting the lifetime in seconds of the `c_nonce`.
 * `authorization_details`: REQUIRED when `authorization_details` parameter is used to request issuance of a certain Credential type as defined in (#authorization-details). MUST NOT be used otherwise. An array of objects as defined in Section 7 of [@!RFC9396]. In addition to the parameters defined in (#authorization-details), this specification defines the following parameter to be used with authorization details type `openid_credential` in the Token Response:
-  * `credential_identifiers`: OPTIONAL. Array of strings that each uniquely identify a Credential instance that can be issued using Access Token returned in this response. Each Credential instance is a unique Credential described using the same entry in the `credential_configurations_supported` Credential Issuer metadata, but can contain different claim values or different subset of claims within the claimset identified by the Credential type. This parameter can also be used to simplify the Credential Request, since as defined in (#credential_request) `credential_identifier` parameter replaces `format` and any other Credential format specific parameters in the Credential Request. When received, the Wallet MUST use these values together with an Access Token in the subsequent Credential Request(s).
+  * `credential_identifiers`: OPTIONAL. Array of strings, each uniquely identifying a Credential that can be issued using the Access Token returned in this response. Each of these Credentials corresponds to the same entry in the `credential_configurations_supported` Credential Issuer metadata but can contain different claim values or a different subset of claims within the claimset identified by that Credential type. This parameter can be used to simplify the Credential Request, as defined in (#credential_request), where the `credential_identifier` parameter replaces the format and any other Credential format-specific parameters in the Credential Request. When received, the Wallet MUST use these values together with an Access Token in subsequent Credential Requests.
 
 Note: Credential Instance identifier(s) cannot be used when `scope` parameter is used in the Authorization Request to request issuance of a Credential.