Merge pull request #380 from openid/clarify-credential-offer

Clarify language around opening Credential Offer Endpoint

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

@@ -335,7 +335,9 @@ This endpoint is used by a Credential Issuer that is already interacting with an
 
 ## Credential Offer {#credential-offer}
 
-The Credential Issuer sends Credential Offer using an HTTP GET request or an HTTP redirect to the Wallet's Credential Offer Endpoint defined in (#client-metadata).
+The Credential Issuer makes a Credential Offer by allowing the End-User to invoke the Wallet using the Wallet's Credential Offer Endpoint defined in (#client-metadata). For example, by clicking a link and/or rendering a QR code containing the Credential Offer that the End-User can scan in a wallet or an arbitrary camera application.
+
+Credential Issuers MAY also communicate Credential Offers directly to a Wallet's backend but any mechanism for doing so is currently outside the scope of this specification.
 
 The Credential Offer object, which is a JSON-encoded object with the Credential Offer parameters, can be sent by value or by reference.
 
@@ -344,8 +346,6 @@ The Credential Offer contains a single URI query parameter, either `credential_o
 * `credential_offer`: Object with the Credential Offer parameters. This MUST NOT be present when the `credential_offer_uri` parameter is present.
 * `credential_offer_uri`: String that is a URL using the `https` scheme referencing a resource containing a JSON object with the Credential Offer parameters. This MUST NOT be present when the `credential_offer` parameter is present.
 
-The Credential Issuer MAY render a QR code containing the Credential Offer that can be scanned by the End-User using a Wallet, or a link that the End-User can click.
-
 For security considerations, see (#credential-offer-security).
 
 ### Credential Offer Parameters {#credential-offer-parameters}