diff --git a/core/src/main/kotlin/net/corda/core/node/services/IdentityService.kt b/core/src/main/kotlin/net/corda/core/node/services/IdentityService.kt
index c74c50fdec..3b7eab103a 100644
--- a/core/src/main/kotlin/net/corda/core/node/services/IdentityService.kt
+++ b/core/src/main/kotlin/net/corda/core/node/services/IdentityService.kt
@@ -178,6 +178,11 @@ interface IdentityService {
     @Suspendable
     fun externalIdForPublicKey(publicKey: PublicKey): UUID?
 
+    /**
+     * This method returns all the [PublicKey]s which have been mapped to the supplied external ID.
+     *
+     * @param externalId the external ID to lookup [PublicKey]s for
+     */
     fun publicKeysForExternalId(externalId: UUID): Iterable<PublicKey>
 }
 
diff --git a/docs/source/changelog.rst b/docs/source/changelog.rst
index 93e0029fc4..dc00f37cfc 100644
--- a/docs/source/changelog.rst
+++ b/docs/source/changelog.rst
@@ -12,9 +12,17 @@ Unreleased
   when rethrown on the RPC client.
 
 * Introduced a new parameter ``externalIds: List<UUID>`` to ``VaultQueryCriteria`` which allows CorDapp developers to constrain queries
-  to a specified set of external IDs.
+  to a specified set of external IDs. This feature should be used when querying states for a particular "account" (see accounts CorDapp for
+  further information).
 
-* Introduced a new API on ``KeyManagementService`` which facilitates lookups of ``PublicKey`` s to ``externalId`` s (Account IDs).
+* Introduced a new API on ``IdentityService`` called ``RegisterKey`` which maps a ``PublicKey`` to a specified ``CordaX500Name`` and to an
+  optional ``UUID`` (external Id).
+
+* Introduced a new API on ``IdentityService`` called ``publicKeyToExternalId` which facilitates lookups of ``PublicKey`` s to
+  ``externalId`` s (Account IDs).
+
+* Introduced a new API on ``IdentityService`` called ``publicKeysForExternalId`` which returns all the ``PublicKey`` s associated with a
+  particular external ID.
 
 * ``StatePointer`` has been marked as ```@DoNotImplement``, which was an omission in the original release.