diff --git a/IETF-RFC.md b/IETF-RFC.md
index d5b6214..538ed4b 100644
--- a/IETF-RFC.md
+++ b/IETF-RFC.md
@@ -137,11 +137,11 @@ Whereas the precise syntax of the Invite Message and the Invite Acceptance Gestu
 * to the `/invited-accepted` path in the Invite Sender OCM Server's OCM API
 * using `application/json` as the `Content-Type` HTTP request header
 * its request body containing a JSON document representing an object with the following string fields:
-  * `recipientProvider` - FQDN of the Invite Receiver OCM Server
-  * `token` - the Invite Token. The Invite Sender OCM Server SHOULD recall which Invite Sender OCM Address this token was linked to
-  * `userID` - the Invite Receiver's identifier at their OCM Server
-  * `email` - non-normative / informational; an email address for the Invite Receiver. Not necessarily at the same FQDN as their OCM Server
-  * `name` - human-readable name of the Invite Receiver, as a suggestion for display in the Invite Sender's address book
+  * REQUIRED: `recipientProvider` - FQDN of the Invite Receiver OCM Server
+  * REQUIRED: `token` - the Invite Token. The Invite Sender OCM Server SHOULD recall which Invite Sender OCM Address this token was linked to
+  * REQUIRED: `userID` - the Invite Receiver's identifier at their OCM Server
+  * REQUIRED: `email` - non-normative / informational; an email address for the Invite Receiver. Not necessarily at the same FQDN as their OCM Server
+  * REQUIRED: `name` - human-readable name of the Invite Receiver, as a suggestion for display in the Invite Sender's address book
 * using TLS
 * using [httpsig](https://datatracker.ietf.org/doc/html/draft-cavage-http-signatures-12)
 
@@ -157,9 +157,9 @@ The Invite Acceptance Response SHOULD be a HTTP response:
 * in response to the Invite Acceptance Request
 * using `application/json` as the `Content-Type` HTTP response header
 * its response body containing a JSON document representing an object with the following string fields:
-  * `userID` - the Invite Sender's identifier at their OCM Server
-  * `email` - non-normative / informational; an email address for the Invite Sender. Not necessarily at the same FQDN as their OCM Server
-  * `name` - human-readable name of the Invite Sender, as a suggestion for display in the Invite Receiver's address book
+  * REQUIRED: `userID` - the Invite Sender's identifier at their OCM Server
+  * REQUIRED: `email` - non-normative / informational; an email address for the Invite Sender. Not necessarily at the same FQDN as their OCM Server
+  * REQUIRED: `name` - human-readable name of the Invite Sender, as a suggestion for display in the Invite Receiver's address book
 
 A 200 response status means the Invitation Acceptance Request was successful.
 A 400 response status means the Invitation Token is invalid or does not exist.
diff --git a/spec.yaml b/spec.yaml
index 320dc48..85ce807 100644
--- a/spec.yaml
+++ b/spec.yaml
@@ -690,45 +690,53 @@ definitions:
         providerId: "51dc30ddc473d43a6011e9ebba6ca770"
   AcceptedInvite:
     type: object
-    allOf:
-      - properties:
-          recipientProvider:
-            type: string
-            format: fqdn
-            description: FQDN of the receiver OCM service.
-            example: receiver.org
-          token:
-            type: string
-            description: Token received in the invite
-            example: xyz
-          userID:
-            type: string
-            description: Unique ID to identify the Invite Receiver at their OCM Server.
-            example: 51dc30ddc473d43a6011e9ebba6ca770
-          email:
-            type: string
-            description: Email address of the Invite Receiver.
-            example: richard@gmail.com
-          name:
-            type: string
-            description: Name of the Invite Receiver.
-            example: Richard Feynman
+    required:
+      - recipientProvider
+      - token
+      - userID
+      - email
+      - name
+    properties:
+      recipientProvider:
+        type: string
+        format: fqdn
+        description: FQDN of the receiver OCM service.
+        example: receiver.org
+      token:
+        type: string
+        description: Token received in the invite
+        example: xyz
+      userID:
+        type: string
+        description: Unique ID to identify the Invite Receiver at their OCM Server.
+        example: 51dc30ddc473d43a6011e9ebba6ca770
+      email:
+        type: string
+        description: Email address of the Invite Receiver.
+        example: richard@gmail.com
+      name:
+        type: string
+        description: Name of the Invite Receiver.
+        example: Richard Feynman
   AcceptedInviteResponse:
     type: object
-    allOf:
-      - properties:
-          userID:
-            type: string
-            description: Unique ID to identify the Invite Sender at their OCM Server.
-            example: 9302
-          email:
-            type: string
-            description: Email ID of the Invite Sender.
-            example: john@sender.org
-          name:
-            type: string
-            description: Name of the Invite Sender.
-            example: John Doe
+    required:
+      - userID
+      - email
+      - name
+    properties:
+      userID:
+        type: string
+        description: Unique ID to identify the Invite Sender at their OCM Server.
+        example: 9302
+      email:
+        type: string
+        description: Email ID of the Invite Sender.
+        example: john@sender.org
+      name:
+        type: string
+        description: Name of the Invite Sender.
+        example: John Doe
   TokenRequest:
     type: object
     properties: