diff --git a/openid-caep-1_0.md b/openid-caep-1_0.md
index 3624fb7..2a2be39 100644
--- a/openid-caep-1_0.md
+++ b/openid-caep-1_0.md
@@ -734,9 +734,6 @@ The `event_timestamp` in this event type specifies the time at which the session
 ### Event Specific Claims {#session-established-event-specific-claims}
 The following optional claims MAY be included in the Session Established event:
 
-ips
-: The array of IP addresses of the user as observed by the Transmitter. The value MUST be in the format of an array of strings, each one of which represents the RFC 4001 {{RFC4001}} string represetation of an IP address. (**NOTE**, this can be different from the one observed by the Receiver for the same user because of network translation)
-
 fp_ua
 : Fingerprint of the user agent computed by the Transmitter. (**NOTE**, this is not to identify the session, but to present some qualities of the session)
 
@@ -766,7 +763,6 @@ The following is a non-normative example of the `session-established` event type
     },
     "events": {
         "https://schemas.openid.net/secevent/caep/event-type/session-established": {
-          "ips": ["192.168.1.12", "10.1.1.1"],
           "fp_ua": "abb0b6e7da81a42233f8f2b1a8ddb1b9a4c81611",
           "acr": "AAL2",
           "amr": "otp",
@@ -789,9 +785,6 @@ The Session Presented event signifies that the Transmitter has observed the sess
 ### Event Specific Claims {#session-presented-event-specific-claims}
 The following optional claims MAY be present in a Session Presented event:
 
-ips
-: The array of IP addresses of the user as observed by the Transmitter. The value MUST be in the format of an array of strings, each one of which represents the RFC 4001 {{RFC4001}} string represetation of an IP address. (**NOTE**, this can be different from the one observed by the Receiver for the same user because of network translation)
-
 fp_ua
 : Fingerprint of the user agent computed by the Transmitter. (**NOTE**, this is not to identify the session, but to present some qualities of the session)
 
@@ -814,7 +807,6 @@ The following is a non-normative example of a Session Presented event:
     },
     "events": {
         "https://schemas.openid.net/secevent/caep/event-type/session-presented": {
-          "ips": ["192.168.1.12","10.1.1.1"],
           "fp_ua": "abb0b6e7da81a42233f8f2b1a8ddb1b9a4c81611",
           "ext_id": "12345",
           "event_timestamp": 1615304991643
diff --git a/openid-sharedsignals-framework-1_0.md b/openid-sharedsignals-framework-1_0.md
index d293f33..602e4db 100644
--- a/openid-sharedsignals-framework-1_0.md
+++ b/openid-sharedsignals-framework-1_0.md
@@ -115,6 +115,7 @@ normative:
   RFC8936:
   RFC9110:
   RFC9493:
+  RFC4001:
   CAEP:
     author:
     -
@@ -386,6 +387,31 @@ Subject Identifier Format.
     "assertion_id": "_8e8dc5f69a98cc4c1ff3427e5ce34606fd672f91e6"
 }
 
+~~~
+{: #sub-id-ips title="Example: 'ips' Subject Identifier"}
+
+### IP Addresses Subject Identifier Format {#sub-id-ips}
+
+The "IP addresses" Subject Identifier Format specifies an array of IP addresses observed by the Transmitter.
+Subject Identifiers of this format MUST contain the following members:
+
+ips
+
+> REQUIRED. The array of IP addresses of the subject as observed by the Transmitter. The value MUST be in the format of an array of strings, each one of which represents the {{RFC4001}} string representation of an IP address.
+
+
+The "IP addresses" Subject Identifier Format is identified by the name
+"ips".
+
+Below is a non-normative example of Subject Identifier for the "IP addresses"
+Subject Identifier Format.
+
+~~~ json
+{
+    "format": "ips",
+    "ips": ["10.29.37.75", "98.27.134.237"]
+}
+
 ~~~
 {: #sub-id-samlassertionid title="Example: 'saml_assertion_id' Subject Identifier"}