diff --git a/manifest/manifestlist/manifestlist.go b/manifest/manifestlist/manifestlist.go
index 3303c6be..0d5c9af1 100644
--- a/manifest/manifestlist/manifestlist.go
+++ b/manifest/manifestlist/manifestlist.go
@@ -89,9 +89,6 @@ type ManifestList struct {
 
 	// Config references the image configuration as a blob.
 	Manifests []ManifestDescriptor `json:"manifests"`
-
-	// Annotations contains arbitrary metadata for the image index.
-	Annotations map[string]string `json:"annotations,omitempty"`
 }
 
 // References returns the distribution descriptors for the referenced image
diff --git a/manifest/manifestlist/manifestlist_test.go b/manifest/manifestlist/manifestlist_test.go
index 6909895b..720b911b 100644
--- a/manifest/manifestlist/manifestlist_test.go
+++ b/manifest/manifestlist/manifestlist_test.go
@@ -111,7 +111,12 @@ func TestManifestList(t *testing.T) {
 	}
 }
 
-// TODO (mikebrow): add annotations on the index and individual manifests
+// TODO (mikebrow): add annotations on the manifest list (index) and support for
+// empty platform structs (move to Platform *Platform `json:"platform,omitempty"`
+// from current Platform PlatformSpec `json:"platform"`) in the manifest descriptor.
+// Requires changes to docker/distribution/manifest/manifestlist.ManifestList and .ManifestDescriptor
+// and associated serialization APIs in manifestlist.go. Or split the OCI index and
+// docker manifest list implementations, which would require a lot of refactoring.
 var expectedOCIImageIndexSerialization = []byte(`{
    "schemaVersion": 2,
    "mediaType": "application/vnd.oci.image.index.v1+json",
@@ -128,10 +133,25 @@ var expectedOCIImageIndexSerialization = []byte(`{
             ]
          }
       },
+      {
+         "mediaType": "application/vnd.oci.image.manifest.v1+json",
+         "size": 985,
+         "digest": "sha256:1a9ec845ee94c202b2d5da74a24f0ed2058318bfa9879fa541efaecba272e86b",
+         "annotations": {
+            "platform": "none"
+         },
+         "platform": {
+            "architecture": "",
+            "os": ""
+         }
+      },
       {
          "mediaType": "application/vnd.oci.image.manifest.v1+json",
          "size": 2392,
          "digest": "sha256:6346340964309634683409684360934680934608934608934608934068934608",
+         "annotations": {
+            "what": "for"
+         },
          "platform": {
             "architecture": "sun4m",
             "os": "sunos"
@@ -156,9 +176,18 @@ func TestOCIImageIndex(t *testing.T) {
 		},
 		{
 			Descriptor: distribution.Descriptor{
-				Digest:    "sha256:6346340964309634683409684360934680934608934608934608934068934608",
-				Size:      2392,
-				MediaType: "application/vnd.oci.image.manifest.v1+json",
+				Digest:      "sha256:1a9ec845ee94c202b2d5da74a24f0ed2058318bfa9879fa541efaecba272e86b",
+				Size:        985,
+				MediaType:   "application/vnd.oci.image.manifest.v1+json",
+				Annotations: map[string]string{"platform": "none"},
+			},
+		},
+		{
+			Descriptor: distribution.Descriptor{
+				Digest:      "sha256:6346340964309634683409684360934680934608934608934608934068934608",
+				Size:        2392,
+				MediaType:   "application/vnd.oci.image.manifest.v1+json",
+				Annotations: map[string]string{"what": "for"},
 			},
 			Platform: PlatformSpec{
 				Architecture: "sun4m",
@@ -190,7 +219,7 @@ func TestOCIImageIndex(t *testing.T) {
 
 	// Check that the canonical field has the expected value.
 	if !bytes.Equal(expectedOCIImageIndexSerialization, canonical) {
-		t.Fatalf("manifest bytes not equal: %q != %q", string(canonical), string(expectedOCIImageIndexSerialization))
+		t.Fatalf("manifest bytes not equal to expected: %q != %q", string(canonical), string(expectedOCIImageIndexSerialization))
 	}
 
 	var unmarshalled DeserializedManifestList
@@ -203,7 +232,7 @@ func TestOCIImageIndex(t *testing.T) {
 	}
 
 	references := deserialized.References()
-	if len(references) != 2 {
+	if len(references) != 3 {
 		t.Fatalf("unexpected number of references: %d", len(references))
 	}
 	for i := range references {
diff --git a/registry/storage/ocimanifesthandler.go b/registry/storage/ocimanifesthandler.go
index c61beb4b..f1fbcead 100644
--- a/registry/storage/ocimanifesthandler.go
+++ b/registry/storage/ocimanifesthandler.go
@@ -3,6 +3,7 @@ package storage
 import (
 	"encoding/json"
 	"fmt"
+	"net/url"
 
 	"github.com/docker/distribution"
 	"github.com/docker/distribution/context"
@@ -79,6 +80,22 @@ func (ms *ocischemaManifestHandler) verifyManifest(ctx context.Context, mnfst oc
 		var err error
 
 		switch descriptor.MediaType {
+		case v1.MediaTypeImageLayer, v1.MediaTypeImageLayerGzip, v1.MediaTypeImageLayerNonDistributable, v1.MediaTypeImageLayerNonDistributableGzip:
+			allow := ms.manifestURLs.allow
+			deny := ms.manifestURLs.deny
+			for _, u := range descriptor.URLs {
+				var pu *url.URL
+				pu, err = url.Parse(u)
+				if err != nil || (pu.Scheme != "http" && pu.Scheme != "https") || pu.Fragment != "" || (allow != nil && !allow.MatchString(u)) || (deny != nil && deny.MatchString(u)) {
+					err = errInvalidURL
+					break
+				}
+			}
+			if err == nil && len(descriptor.URLs) == 0 {
+				// If no URLs, require that the blob exists
+				_, err = blobsService.Stat(ctx, descriptor.Digest)
+			}
+
 		case v1.MediaTypeImageManifest:
 			var exists bool
 			exists, err = manifestService.Exists(ctx, descriptor.Digest)
diff --git a/registry/storage/ocimanifesthandler_test.go b/registry/storage/ocimanifesthandler_test.go
index 047f1c3a..302294af 100644
--- a/registry/storage/ocimanifesthandler_test.go
+++ b/registry/storage/ocimanifesthandler_test.go
@@ -52,6 +52,11 @@ func TestVerifyOCIManifestNonDistributableLayer(t *testing.T) {
 	}
 
 	cases := []testcase{
+		{
+			nonDistributableLayer,
+			nil,
+			distribution.ErrManifestBlobUnknown{Digest: nonDistributableLayer.Digest},
+		},
 		{
 			layer,
 			[]string{"http://foo/bar"},
@@ -60,37 +65,37 @@ func TestVerifyOCIManifestNonDistributableLayer(t *testing.T) {
 		{
 			nonDistributableLayer,
 			[]string{"file:///local/file"},
-			nil,
+			errInvalidURL,
 		},
 		{
 			nonDistributableLayer,
 			[]string{"http://foo/bar#baz"},
-			nil,
+			errInvalidURL,
 		},
 		{
 			nonDistributableLayer,
 			[]string{""},
-			nil,
+			errInvalidURL,
 		},
 		{
 			nonDistributableLayer,
 			[]string{"https://foo/bar", ""},
-			nil,
+			errInvalidURL,
 		},
 		{
 			nonDistributableLayer,
 			[]string{"", "https://foo/bar"},
-			nil,
+			errInvalidURL,
 		},
 		{
 			nonDistributableLayer,
 			[]string{"http://nope/bar"},
-			nil,
+			errInvalidURL,
 		},
 		{
 			nonDistributableLayer,
 			[]string{"http://foo/nope"},
-			nil,
+			errInvalidURL,
 		},
 		{
 			nonDistributableLayer,
@@ -122,6 +127,8 @@ func TestVerifyOCIManifestNonDistributableLayer(t *testing.T) {
 				if _, ok = verr[1].(distribution.ErrManifestBlobUnknown); ok {
 					err = verr[0]
 				}
+			} else if len(verr) == 1 {
+				err = verr[0]
 			}
 		}
 		if err != c.Err {