diff --git a/reference/helpers.go b/reference/helpers.go
index dd7ee0ea6..a8f46cedd 100644
--- a/reference/helpers.go
+++ b/reference/helpers.go
@@ -10,3 +10,21 @@ func IsNameOnly(ref Named) bool {
 	}
 	return true
 }
+
+// FamiliarName returns the familiar name string
+// for the given named, familiarizing if needed.
+func FamiliarName(ref Named) string {
+	if nn, ok := ref.(NormalizedNamed); ok {
+		return nn.Familiar().Name()
+	}
+	return ref.Name()
+}
+
+// FamiliarString returns the familiar string representation
+// for the given reference, familiarizing if needed.
+func FamiliarString(ref Reference) string {
+	if nn, ok := ref.(NormalizedNamed); ok {
+		return nn.Familiar().String()
+	}
+	return ref.String()
+}
diff --git a/reference/normalize.go b/reference/normalize.go
index b19a34e3b..7fc6382b1 100644
--- a/reference/normalize.go
+++ b/reference/normalize.go
@@ -1,9 +1,124 @@
 package reference
 
-var (
-	defaultTag = "latest"
+import (
+	"errors"
+	"fmt"
+	"strings"
+
+	"github.com/docker/distribution/digest"
 )
 
+var (
+	legacyDefaultDomain = "index.docker.io"
+	defaultDomain       = "docker.io"
+	defaultRepoPrefix   = "library/"
+	defaultTag          = "latest"
+)
+
+// NormalizedNamed represents a name which has been
+// normalized and has a familiar form. A familiar name
+// is what is used in Docker UI. An example normalized
+// name is "docker.io/library/ubuntu" and corresponding
+// familiar name of "ubuntu".
+type NormalizedNamed interface {
+	Named
+	Familiar() Named
+}
+
+// ParseNormalizedNamed parses a string into a named reference
+// transforming a familiar name from Docker UI to a fully
+// qualified reference. If the value may be an identifier
+// use ParseAnyReference.
+func ParseNormalizedNamed(s string) (NormalizedNamed, error) {
+	if ok := anchoredIdentifierRegexp.MatchString(s); ok {
+		return nil, fmt.Errorf("invalid repository name (%s), cannot specify 64-byte hexadecimal strings", s)
+	}
+	domain, remainder := splitDockerDomain(s)
+	var remoteName string
+	if tagSep := strings.IndexRune(remainder, ':'); tagSep > -1 {
+		remoteName = remainder[:tagSep]
+	} else {
+		remoteName = remainder
+	}
+	if strings.ToLower(remoteName) != remoteName {
+		return nil, errors.New("invalid reference format: repository name must be lowercase")
+	}
+
+	ref, err := Parse(domain + "/" + remainder)
+	if err != nil {
+		return nil, err
+	}
+	named, isNamed := ref.(NormalizedNamed)
+	if !isNamed {
+		return nil, fmt.Errorf("reference %s has no name", ref.String())
+	}
+	return named, nil
+}
+
+// splitDockerDomain splits a repository name to domain and remotename string.
+// If no valid domain is found, the default domain is used. Repository name
+// needs to be already validated before.
+func splitDockerDomain(name string) (domain, remainder string) {
+	i := strings.IndexRune(name, '/')
+	if i == -1 || (!strings.ContainsAny(name[:i], ".:") && name[:i] != "localhost") {
+		domain, remainder = defaultDomain, name
+	} else {
+		domain, remainder = name[:i], name[i+1:]
+	}
+	if domain == legacyDefaultDomain {
+		domain = defaultDomain
+	}
+	if domain == defaultDomain && !strings.ContainsRune(remainder, '/') {
+		remainder = defaultRepoPrefix + remainder
+	}
+	return
+}
+
+// familiarizeName returns a shortened version of the name familiar
+// to to the Docker UI. Familiar names have the default domain
+// "docker.io" and "library/" repository prefix removed.
+// For example, "docker.io/library/redis" will have the familiar
+// name "redis" and "docker.io/dmcgowan/myapp" will be "dmcgowan/myapp".
+// Returns a familiarized named only reference.
+func familiarizeName(named NamedRepository) repository {
+	repo := repository{
+		domain: named.Domain(),
+		path:   named.Path(),
+	}
+
+	if repo.domain == defaultDomain {
+		repo.domain = ""
+		repo.path = strings.TrimPrefix(repo.path, defaultRepoPrefix)
+	}
+	return repo
+}
+
+func (r reference) Familiar() Named {
+	return reference{
+		NamedRepository: familiarizeName(r.NamedRepository),
+		tag:             r.tag,
+		digest:          r.digest,
+	}
+}
+
+func (r repository) Familiar() Named {
+	return familiarizeName(r)
+}
+
+func (t taggedReference) Familiar() Named {
+	return taggedReference{
+		NamedRepository: familiarizeName(t.NamedRepository),
+		tag:             t.tag,
+	}
+}
+
+func (c canonicalReference) Familiar() Named {
+	return canonicalReference{
+		NamedRepository: familiarizeName(c.NamedRepository),
+		digest:          c.digest,
+	}
+}
+
 // EnsureTagged adds the default tag "latest" to a reference if it only has
 // a repo name.
 func EnsureTagged(ref Named) NamedTagged {
@@ -20,3 +135,33 @@ func EnsureTagged(ref Named) NamedTagged {
 	}
 	return namedTagged
 }
+
+// ParseAnyReference parses a reference string as a possible identifier,
+// full digest, or familiar name.
+func ParseAnyReference(ref string) (Reference, error) {
+	if ok := anchoredIdentifierRegexp.MatchString(ref); ok {
+		return digestReference("sha256:" + ref), nil
+	}
+	if dgst, err := digest.ParseDigest(ref); err == nil {
+		return digestReference(dgst), nil
+	}
+
+	return ParseNormalizedNamed(ref)
+}
+
+// ParseAnyReferenceWithSet parses a reference string as a possible short
+// identifier to be matched in a digest set, a full digest, or familiar name.
+func ParseAnyReferenceWithSet(ref string, ds *digest.Set) (Reference, error) {
+	if ok := anchoredShortIdentifierRegexp.MatchString(ref); ok {
+		dgst, err := ds.Lookup(ref)
+		if err == nil {
+			return digestReference(dgst), nil
+		}
+	} else {
+		if dgst, err := digest.ParseDigest(ref); err == nil {
+			return digestReference(dgst), nil
+		}
+	}
+
+	return ParseNormalizedNamed(ref)
+}
diff --git a/reference/normalize_test.go b/reference/normalize_test.go
new file mode 100644
index 000000000..f4e09b04b
--- /dev/null
+++ b/reference/normalize_test.go
@@ -0,0 +1,436 @@
+package reference
+
+import (
+	"testing"
+
+	"github.com/docker/distribution/digest"
+)
+
+func TestValidateReferenceName(t *testing.T) {
+	validRepoNames := []string{
+		"docker/docker",
+		"library/debian",
+		"debian",
+		"docker.io/docker/docker",
+		"docker.io/library/debian",
+		"docker.io/debian",
+		"index.docker.io/docker/docker",
+		"index.docker.io/library/debian",
+		"index.docker.io/debian",
+		"127.0.0.1:5000/docker/docker",
+		"127.0.0.1:5000/library/debian",
+		"127.0.0.1:5000/debian",
+		"thisisthesongthatneverendsitgoesonandonandonthisisthesongthatnev",
+
+		// This test case was moved from invalid to valid since it is valid input
+		// when specified with a hostname, it removes the ambiguity from about
+		// whether the value is an identifier or repository name
+		"docker.io/1a3f5e7d9c1b3a5f7e9d1c3b5a7f9e1d3c5b7a9f1e3d5d7c9b1a3f5e7d9c1b3a",
+	}
+	invalidRepoNames := []string{
+		"https://github.com/docker/docker",
+		"docker/Docker",
+		"-docker",
+		"-docker/docker",
+		"-docker.io/docker/docker",
+		"docker///docker",
+		"docker.io/docker/Docker",
+		"docker.io/docker///docker",
+		"1a3f5e7d9c1b3a5f7e9d1c3b5a7f9e1d3c5b7a9f1e3d5d7c9b1a3f5e7d9c1b3a",
+	}
+
+	for _, name := range invalidRepoNames {
+		_, err := ParseNormalizedNamed(name)
+		if err == nil {
+			t.Fatalf("Expected invalid repo name for %q", name)
+		}
+	}
+
+	for _, name := range validRepoNames {
+		_, err := ParseNormalizedNamed(name)
+		if err != nil {
+			t.Fatalf("Error parsing repo name %s, got: %q", name, err)
+		}
+	}
+}
+
+func TestValidateRemoteName(t *testing.T) {
+	validRepositoryNames := []string{
+		// Sanity check.
+		"docker/docker",
+
+		// Allow 64-character non-hexadecimal names (hexadecimal names are forbidden).
+		"thisisthesongthatneverendsitgoesonandonandonthisisthesongthatnev",
+
+		// Allow embedded hyphens.
+		"docker-rules/docker",
+
+		// Allow multiple hyphens as well.
+		"docker---rules/docker",
+
+		//Username doc and image name docker being tested.
+		"doc/docker",
+
+		// single character names are now allowed.
+		"d/docker",
+		"jess/t",
+
+		// Consecutive underscores.
+		"dock__er/docker",
+	}
+	for _, repositoryName := range validRepositoryNames {
+		_, err := ParseNormalizedNamed(repositoryName)
+		if err != nil {
+			t.Errorf("Repository name should be valid: %v. Error: %v", repositoryName, err)
+		}
+	}
+
+	invalidRepositoryNames := []string{
+		// Disallow capital letters.
+		"docker/Docker",
+
+		// Only allow one slash.
+		"docker///docker",
+
+		// Disallow 64-character hexadecimal.
+		"1a3f5e7d9c1b3a5f7e9d1c3b5a7f9e1d3c5b7a9f1e3d5d7c9b1a3f5e7d9c1b3a",
+
+		// Disallow leading and trailing hyphens in namespace.
+		"-docker/docker",
+		"docker-/docker",
+		"-docker-/docker",
+
+		// Don't allow underscores everywhere (as opposed to hyphens).
+		"____/____",
+
+		"_docker/_docker",
+
+		// Disallow consecutive periods.
+		"dock..er/docker",
+		"dock_.er/docker",
+		"dock-.er/docker",
+
+		// No repository.
+		"docker/",
+
+		//namespace too long
+		"this_is_not_a_valid_namespace_because_its_lenth_is_greater_than_255_this_is_not_a_valid_namespace_because_its_lenth_is_greater_than_255_this_is_not_a_valid_namespace_because_its_lenth_is_greater_than_255_this_is_not_a_valid_namespace_because_its_lenth_is_greater_than_255/docker",
+	}
+	for _, repositoryName := range invalidRepositoryNames {
+		if _, err := ParseNormalizedNamed(repositoryName); err == nil {
+			t.Errorf("Repository name should be invalid: %v", repositoryName)
+		}
+	}
+}
+
+func TestParseRepositoryInfo(t *testing.T) {
+	type tcase struct {
+		RemoteName, FamiliarName, FullName, AmbiguousName, Domain string
+	}
+
+	tcases := []tcase{
+		{
+			RemoteName:    "fooo/bar",
+			FamiliarName:  "fooo/bar",
+			FullName:      "docker.io/fooo/bar",
+			AmbiguousName: "index.docker.io/fooo/bar",
+			Domain:        "docker.io",
+		},
+		{
+			RemoteName:    "library/ubuntu",
+			FamiliarName:  "ubuntu",
+			FullName:      "docker.io/library/ubuntu",
+			AmbiguousName: "library/ubuntu",
+			Domain:        "docker.io",
+		},
+		{
+			RemoteName:    "nonlibrary/ubuntu",
+			FamiliarName:  "nonlibrary/ubuntu",
+			FullName:      "docker.io/nonlibrary/ubuntu",
+			AmbiguousName: "",
+			Domain:        "docker.io",
+		},
+		{
+			RemoteName:    "other/library",
+			FamiliarName:  "other/library",
+			FullName:      "docker.io/other/library",
+			AmbiguousName: "",
+			Domain:        "docker.io",
+		},
+		{
+			RemoteName:    "private/moonbase",
+			FamiliarName:  "127.0.0.1:8000/private/moonbase",
+			FullName:      "127.0.0.1:8000/private/moonbase",
+			AmbiguousName: "",
+			Domain:        "127.0.0.1:8000",
+		},
+		{
+			RemoteName:    "privatebase",
+			FamiliarName:  "127.0.0.1:8000/privatebase",
+			FullName:      "127.0.0.1:8000/privatebase",
+			AmbiguousName: "",
+			Domain:        "127.0.0.1:8000",
+		},
+		{
+			RemoteName:    "private/moonbase",
+			FamiliarName:  "example.com/private/moonbase",
+			FullName:      "example.com/private/moonbase",
+			AmbiguousName: "",
+			Domain:        "example.com",
+		},
+		{
+			RemoteName:    "privatebase",
+			FamiliarName:  "example.com/privatebase",
+			FullName:      "example.com/privatebase",
+			AmbiguousName: "",
+			Domain:        "example.com",
+		},
+		{
+			RemoteName:    "private/moonbase",
+			FamiliarName:  "example.com:8000/private/moonbase",
+			FullName:      "example.com:8000/private/moonbase",
+			AmbiguousName: "",
+			Domain:        "example.com:8000",
+		},
+		{
+			RemoteName:    "privatebasee",
+			FamiliarName:  "example.com:8000/privatebasee",
+			FullName:      "example.com:8000/privatebasee",
+			AmbiguousName: "",
+			Domain:        "example.com:8000",
+		},
+		{
+			RemoteName:    "library/ubuntu-12.04-base",
+			FamiliarName:  "ubuntu-12.04-base",
+			FullName:      "docker.io/library/ubuntu-12.04-base",
+			AmbiguousName: "index.docker.io/library/ubuntu-12.04-base",
+			Domain:        "docker.io",
+		},
+	}
+
+	for _, tcase := range tcases {
+		refStrings := []string{tcase.FamiliarName, tcase.FullName}
+		if tcase.AmbiguousName != "" {
+			refStrings = append(refStrings, tcase.AmbiguousName)
+		}
+
+		var refs []NormalizedNamed
+		for _, r := range refStrings {
+			named, err := ParseNormalizedNamed(r)
+			if err != nil {
+				t.Fatal(err)
+			}
+			refs = append(refs, named)
+		}
+
+		for _, r := range refs {
+			if expected, actual := tcase.FamiliarName, r.Familiar().Name(); expected != actual {
+				t.Fatalf("Invalid normalized reference for %q. Expected %q, got %q", r, expected, actual)
+			}
+			if expected, actual := tcase.FullName, r.String(); expected != actual {
+				t.Fatalf("Invalid canonical reference for %q. Expected %q, got %q", r, expected, actual)
+			}
+			if expected, actual := tcase.Domain, Domain(r); expected != actual {
+				t.Fatalf("Invalid domain for %q. Expected %q, got %q", r, expected, actual)
+			}
+			if expected, actual := tcase.RemoteName, Path(r); expected != actual {
+				t.Fatalf("Invalid remoteName for %q. Expected %q, got %q", r, expected, actual)
+			}
+
+		}
+	}
+}
+
+func TestParseReferenceWithTagAndDigest(t *testing.T) {
+	shortRef := "busybox:latest@sha256:86e0e091d0da6bde2456dbb48306f3956bbeb2eae1b5b9a43045843f69fe4aaa"
+	nref, err := ParseNormalizedNamed(shortRef)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if expected, actual := "docker.io/library/"+shortRef, nref.String(); actual != expected {
+		t.Fatalf("Invalid parsed reference for %q: expected %q, got %q", nref, expected, actual)
+	}
+
+	ref := nref.Familiar()
+	if _, isTagged := ref.(NamedTagged); !isTagged {
+		t.Fatalf("Reference from %q should support tag", ref)
+	}
+	if _, isCanonical := ref.(Canonical); !isCanonical {
+		t.Fatalf("Reference from %q should support digest", ref)
+	}
+	if expected, actual := shortRef, ref.String(); actual != expected {
+		t.Fatalf("Invalid parsed reference for %q: expected %q, got %q", ref, expected, actual)
+	}
+}
+
+func TestInvalidReferenceComponents(t *testing.T) {
+	if _, err := ParseNormalizedNamed("-foo"); err == nil {
+		t.Fatal("Expected WithName to detect invalid name")
+	}
+	ref, err := ParseNormalizedNamed("busybox")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err := WithTag(ref, "-foo"); err == nil {
+		t.Fatal("Expected WithName to detect invalid tag")
+	}
+	if _, err := WithDigest(ref, digest.Digest("foo")); err == nil {
+		t.Fatal("Expected WithDigest to detect invalid digest")
+	}
+}
+
+func equalReference(r1, r2 Reference) bool {
+	switch v1 := r1.(type) {
+	case digestReference:
+		if v2, ok := r2.(digestReference); ok {
+			return v1 == v2
+		}
+	case repository:
+		if v2, ok := r2.(repository); ok {
+			return v1 == v2
+		}
+	case taggedReference:
+		if v2, ok := r2.(taggedReference); ok {
+			return v1 == v2
+		}
+	case canonicalReference:
+		if v2, ok := r2.(canonicalReference); ok {
+			return v1 == v2
+		}
+	case reference:
+		if v2, ok := r2.(reference); ok {
+			return v1 == v2
+		}
+	}
+	return false
+}
+
+func TestParseAnyReference(t *testing.T) {
+	tcases := []struct {
+		Reference  string
+		Equivalent string
+		Expected   Reference
+		Digests    []digest.Digest
+	}{
+		{
+			Reference:  "redis",
+			Equivalent: "docker.io/library/redis",
+		},
+		{
+			Reference:  "redis:latest",
+			Equivalent: "docker.io/library/redis:latest",
+		},
+		{
+			Reference:  "docker.io/library/redis:latest",
+			Equivalent: "docker.io/library/redis:latest",
+		},
+		{
+			Reference:  "redis@sha256:dbcc1c35ac38df41fd2f5e4130b32ffdb93ebae8b3dbe638c23575912276fc9c",
+			Equivalent: "docker.io/library/redis@sha256:dbcc1c35ac38df41fd2f5e4130b32ffdb93ebae8b3dbe638c23575912276fc9c",
+		},
+		{
+			Reference:  "docker.io/library/redis@sha256:dbcc1c35ac38df41fd2f5e4130b32ffdb93ebae8b3dbe638c23575912276fc9c",
+			Equivalent: "docker.io/library/redis@sha256:dbcc1c35ac38df41fd2f5e4130b32ffdb93ebae8b3dbe638c23575912276fc9c",
+		},
+		{
+			Reference:  "dmcgowan/myapp",
+			Equivalent: "docker.io/dmcgowan/myapp",
+		},
+		{
+			Reference:  "dmcgowan/myapp:latest",
+			Equivalent: "docker.io/dmcgowan/myapp:latest",
+		},
+		{
+			Reference:  "docker.io/mcgowan/myapp:latest",
+			Equivalent: "docker.io/mcgowan/myapp:latest",
+		},
+		{
+			Reference:  "dmcgowan/myapp@sha256:dbcc1c35ac38df41fd2f5e4130b32ffdb93ebae8b3dbe638c23575912276fc9c",
+			Equivalent: "docker.io/dmcgowan/myapp@sha256:dbcc1c35ac38df41fd2f5e4130b32ffdb93ebae8b3dbe638c23575912276fc9c",
+		},
+		{
+			Reference:  "docker.io/dmcgowan/myapp@sha256:dbcc1c35ac38df41fd2f5e4130b32ffdb93ebae8b3dbe638c23575912276fc9c",
+			Equivalent: "docker.io/dmcgowan/myapp@sha256:dbcc1c35ac38df41fd2f5e4130b32ffdb93ebae8b3dbe638c23575912276fc9c",
+		},
+		{
+			Reference: "dbcc1c35ac38df41fd2f5e4130b32ffdb93ebae8b3dbe638c23575912276fc9c",
+			Expected:  digestReference("sha256:dbcc1c35ac38df41fd2f5e4130b32ffdb93ebae8b3dbe638c23575912276fc9c"),
+		},
+		{
+			Reference: "sha256:dbcc1c35ac38df41fd2f5e4130b32ffdb93ebae8b3dbe638c23575912276fc9c",
+			Expected:  digestReference("sha256:dbcc1c35ac38df41fd2f5e4130b32ffdb93ebae8b3dbe638c23575912276fc9c"),
+		},
+		{
+			Reference:  "dbcc1c35ac38df41fd2f5e4130b32ffdb93ebae8b3dbe638c23575912276fc9",
+			Equivalent: "docker.io/library/dbcc1c35ac38df41fd2f5e4130b32ffdb93ebae8b3dbe638c23575912276fc9",
+		},
+		{
+			Reference: "dbcc1c35ac38df41fd2f5e4130b32ffdb93ebae8b3dbe638c23575912276fc9",
+			Expected:  digestReference("sha256:dbcc1c35ac38df41fd2f5e4130b32ffdb93ebae8b3dbe638c23575912276fc9c"),
+			Digests: []digest.Digest{
+				digest.Digest("sha256:dbcc1c35ac38df41fd2f5e4130b32ffdb93ebae8b3dbe638c23575912276fc9c"),
+				digest.Digest("sha256:abcc1c35ac38df41fd2f5e4130b32ffdb93ebae8b3dbe638c23575912276fc9c"),
+			},
+		},
+		{
+			Reference:  "dbcc1c35ac38df41fd2f5e4130b32ffdb93ebae8b3dbe638c23575912276fc9",
+			Equivalent: "docker.io/library/dbcc1c35ac38df41fd2f5e4130b32ffdb93ebae8b3dbe638c23575912276fc9",
+			Digests: []digest.Digest{
+				digest.Digest("sha256:abcc1c35ac38df41fd2f5e4130b32ffdb93ebae8b3dbe638c23575912276fc9c"),
+			},
+		},
+		{
+			Reference: "dbcc1c",
+			Expected:  digestReference("sha256:dbcc1c35ac38df41fd2f5e4130b32ffdb93ebae8b3dbe638c23575912276fc9c"),
+			Digests: []digest.Digest{
+				digest.Digest("sha256:dbcc1c35ac38df41fd2f5e4130b32ffdb93ebae8b3dbe638c23575912276fc9c"),
+				digest.Digest("sha256:abcc1c35ac38df41fd2f5e4130b32ffdb93ebae8b3dbe638c23575912276fc9c"),
+			},
+		},
+		{
+			Reference:  "dbcc1",
+			Equivalent: "docker.io/library/dbcc1",
+			Digests: []digest.Digest{
+				digest.Digest("sha256:dbcc1c35ac38df41fd2f5e4130b32ffdb93ebae8b3dbe638c23575912276fc9c"),
+				digest.Digest("sha256:abcc1c35ac38df41fd2f5e4130b32ffdb93ebae8b3dbe638c23575912276fc9c"),
+			},
+		},
+		{
+			Reference:  "dbcc1c",
+			Equivalent: "docker.io/library/dbcc1c",
+			Digests: []digest.Digest{
+				digest.Digest("sha256:abcc1c35ac38df41fd2f5e4130b32ffdb93ebae8b3dbe638c23575912276fc9c"),
+			},
+		},
+	}
+
+	for _, tcase := range tcases {
+		var ref Reference
+		var err error
+		if len(tcase.Digests) == 0 {
+			ref, err = ParseAnyReference(tcase.Reference)
+		} else {
+			ds := digest.NewSet()
+			for _, dgst := range tcase.Digests {
+				if err := ds.Add(dgst); err != nil {
+					t.Fatalf("Error adding digest %s: %v", dgst.String(), err)
+				}
+			}
+			ref, err = ParseAnyReferenceWithSet(tcase.Reference, ds)
+		}
+		if err != nil {
+			t.Fatalf("Error parsing reference %s: %v", tcase.Reference, err)
+		}
+
+		expected := tcase.Expected
+		if expected == nil {
+			expected, err = Parse(tcase.Equivalent)
+			if err != nil {
+				t.Fatalf("Error parsing reference %s: %v", tcase.Equivalent, err)
+			}
+		}
+		if !equalReference(ref, expected) {
+			t.Errorf("Unexpected reference %#v, expected %#v", ref, expected)
+		}
+	}
+}
diff --git a/reference/reference.go b/reference/reference.go
index 52da52370..e8aa7730d 100644
--- a/reference/reference.go
+++ b/reference/reference.go
@@ -4,11 +4,11 @@
 // Grammar
 //
 // 	reference                       := name [ ":" tag ] [ "@" digest ]
-//	name                            := [hostname '/'] component ['/' component]*
-//	hostname                        := hostcomponent ['.' hostcomponent]* [':' port-number]
-//	hostcomponent                   := /([a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9-]*[a-zA-Z0-9])/
+//	name                            := [domain '/'] path-component ['/' path-component]*
+//	domain                          := domain-component ['.' domain-component]* [':' port-number]
+//	domain-component                := /([a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9-]*[a-zA-Z0-9])/
 //	port-number                     := /[0-9]+/
-//	component                       := alpha-numeric [separator alpha-numeric]*
+//	path-component                  := alpha-numeric [separator alpha-numeric]*
 // 	alpha-numeric                   := /[a-z0-9]+/
 //	separator                       := /[_.]|__|[-]*/
 //
@@ -19,6 +19,9 @@
 //	digest-algorithm-separator      := /[+.-_]/
 //	digest-algorithm-component      := /[A-Za-z][A-Za-z0-9]*/
 //	digest-hex                      := /[0-9a-fA-F]{32,}/ ; At least 128 bit digest value
+//
+//      identifier                      := /[a-f0-9]{64}/
+//      short-identifier                := /[a-f0-9]{6,64}/
 package reference
 
 import (
@@ -126,23 +129,56 @@ type Digested interface {
 }
 
 // Canonical reference is an object with a fully unique
-// name including a name with hostname and digest
+// name including a name with domain and digest
 type Canonical interface {
 	Named
 	Digest() digest.Digest
 }
 
+// NamedRepository is a reference to a repository with a name.
+// A NamedRepository has both domain and path components.
+type NamedRepository interface {
+	Named
+	Domain() string
+	Path() string
+}
+
+// Domain returns the domain part of the Named reference
+func Domain(named Named) string {
+	if r, ok := named.(NamedRepository); ok {
+		return r.Domain()
+	}
+	domain, _ := splitDomain(named.Name())
+	return domain
+}
+
+// Path returns the name without the domain part of the Named reference
+func Path(named Named) (name string) {
+	if r, ok := named.(NamedRepository); ok {
+		return r.Path()
+	}
+	_, path := splitDomain(named.Name())
+	return path
+}
+
+func splitDomain(name string) (string, string) {
+	match := anchoredNameRegexp.FindStringSubmatch(name)
+	if len(match) != 3 {
+		return "", name
+	}
+	return match[1], match[2]
+}
+
 // SplitHostname splits a named reference into a
 // hostname and name string. If no valid hostname is
 // found, the hostname is empty and the full value
 // is returned as name
+// DEPRECATED: Use Domain or Path
 func SplitHostname(named Named) (string, string) {
-	name := named.Name()
-	match := anchoredNameRegexp.FindStringSubmatch(name)
-	if len(match) != 3 {
-		return "", name
+	if r, ok := named.(NamedRepository); ok {
+		return r.Domain(), r.Path()
 	}
-	return match[1], match[2]
+	return splitDomain(named.Name())
 }
 
 // Parse parses s and returns a syntactically valid Reference.
@@ -164,9 +200,20 @@ func Parse(s string) (Reference, error) {
 		return nil, ErrNameTooLong
 	}
 
+	var repo repository
+
+	nameMatch := anchoredNameRegexp.FindStringSubmatch(matches[1])
+	if nameMatch != nil && len(nameMatch) == 3 {
+		repo.domain = nameMatch[1]
+		repo.path = nameMatch[2]
+	} else {
+		repo.domain = ""
+		repo.path = matches[1]
+	}
+
 	ref := reference{
-		name: matches[1],
-		tag:  matches[2],
+		NamedRepository: repo,
+		tag:             matches[2],
 	}
 	if matches[3] != "" {
 		var err error
@@ -207,10 +254,15 @@ func WithName(name string) (Named, error) {
 	if len(name) > NameTotalLengthMax {
 		return nil, ErrNameTooLong
 	}
-	if !anchoredNameRegexp.MatchString(name) {
+
+	match := anchoredNameRegexp.FindStringSubmatch(name)
+	if match == nil || len(match) != 3 {
 		return nil, ErrReferenceInvalidFormat
 	}
-	return repository(name), nil
+	return repository{
+		domain: match[1],
+		path:   match[2],
+	}, nil
 }
 
 // WithTag combines the name from "name" and the tag from "tag" to form a
@@ -219,16 +271,23 @@ func WithTag(name Named, tag string) (NamedTagged, error) {
 	if !anchoredTagRegexp.MatchString(tag) {
 		return nil, ErrTagInvalidFormat
 	}
+	var repo repository
+	if r, ok := name.(NamedRepository); ok {
+		repo.domain = r.Domain()
+		repo.path = r.Path()
+	} else {
+		repo.path = name.Name()
+	}
 	if canonical, ok := name.(Canonical); ok {
 		return reference{
-			name:   name.Name(),
-			tag:    tag,
-			digest: canonical.Digest(),
+			NamedRepository: repo,
+			tag:             tag,
+			digest:          canonical.Digest(),
 		}, nil
 	}
 	return taggedReference{
-		name: name.Name(),
-		tag:  tag,
+		NamedRepository: repo,
+		tag:             tag,
 	}, nil
 }
 
@@ -238,16 +297,23 @@ func WithDigest(name Named, digest digest.Digest) (Canonical, error) {
 	if !anchoredDigestRegexp.MatchString(digest.String()) {
 		return nil, ErrDigestInvalidFormat
 	}
+	var repo repository
+	if r, ok := name.(NamedRepository); ok {
+		repo.domain = r.Domain()
+		repo.path = r.Path()
+	} else {
+		repo.path = name.Name()
+	}
 	if tagged, ok := name.(Tagged); ok {
 		return reference{
-			name:   name.Name(),
-			tag:    tagged.Tag(),
-			digest: digest,
+			NamedRepository: repo,
+			tag:             tagged.Tag(),
+			digest:          digest,
 		}, nil
 	}
 	return canonicalReference{
-		name:   name.Name(),
-		digest: digest,
+		NamedRepository: repo,
+		digest:          digest,
 	}, nil
 }
 
@@ -263,11 +329,15 @@ func Match(pattern string, ref Reference) (bool, error) {
 
 // TrimNamed removes any tag or digest from the named reference.
 func TrimNamed(ref Named) Named {
-	return repository(ref.Name())
+	domain, path := SplitHostname(ref)
+	return repository{
+		domain: domain,
+		path:   path,
+	}
 }
 
 func getBestReferenceType(ref reference) Reference {
-	if ref.name == "" {
+	if ref.Name() == "" {
 		// Allow digest only references
 		if ref.digest != "" {
 			return digestReference(ref.digest)
@@ -277,16 +347,16 @@ func getBestReferenceType(ref reference) Reference {
 	if ref.tag == "" {
 		if ref.digest != "" {
 			return canonicalReference{
-				name:   ref.name,
-				digest: ref.digest,
+				NamedRepository: ref.NamedRepository,
+				digest:          ref.digest,
 			}
 		}
-		return repository(ref.name)
+		return ref.NamedRepository
 	}
 	if ref.digest == "" {
 		return taggedReference{
-			name: ref.name,
-			tag:  ref.tag,
+			NamedRepository: ref.NamedRepository,
+			tag:             ref.tag,
 		}
 	}
 
@@ -294,17 +364,13 @@ func getBestReferenceType(ref reference) Reference {
 }
 
 type reference struct {
-	name   string
+	NamedRepository
 	tag    string
 	digest digest.Digest
 }
 
 func (r reference) String() string {
-	return r.name + ":" + r.tag + "@" + r.digest.String()
-}
-
-func (r reference) Name() string {
-	return r.name
+	return r.Name() + ":" + r.tag + "@" + r.digest.String()
 }
 
 func (r reference) Tag() string {
@@ -315,14 +381,28 @@ func (r reference) Digest() digest.Digest {
 	return r.digest
 }
 
-type repository string
+type repository struct {
+	domain string
+	path   string
+}
 
 func (r repository) String() string {
-	return string(r)
+	return r.Name()
 }
 
 func (r repository) Name() string {
-	return string(r)
+	if r.domain == "" {
+		return r.path
+	}
+	return r.domain + "/" + r.path
+}
+
+func (r repository) Domain() string {
+	return r.domain
+}
+
+func (r repository) Path() string {
+	return r.path
 }
 
 type digestReference digest.Digest
@@ -336,16 +416,12 @@ func (d digestReference) Digest() digest.Digest {
 }
 
 type taggedReference struct {
-	name string
-	tag  string
+	NamedRepository
+	tag string
 }
 
 func (t taggedReference) String() string {
-	return t.name + ":" + t.tag
-}
-
-func (t taggedReference) Name() string {
-	return t.name
+	return t.Name() + ":" + t.tag
 }
 
 func (t taggedReference) Tag() string {
@@ -353,16 +429,12 @@ func (t taggedReference) Tag() string {
 }
 
 type canonicalReference struct {
-	name   string
+	NamedRepository
 	digest digest.Digest
 }
 
 func (c canonicalReference) String() string {
-	return c.name + "@" + c.digest.String()
-}
-
-func (c canonicalReference) Name() string {
-	return c.name
+	return c.Name() + "@" + c.digest.String()
 }
 
 func (c canonicalReference) Digest() digest.Digest {
diff --git a/reference/reference_test.go b/reference/reference_test.go
index 9d42be0fe..e02702083 100644
--- a/reference/reference_test.go
+++ b/reference/reference_test.go
@@ -21,8 +21,8 @@ func TestReferenceParse(t *testing.T) {
 		err error
 		// repository is the string representation for the reference
 		repository string
-		// hostname is the hostname expected in the reference
-		hostname string
+		// domain is the domain expected in the reference
+		domain string
 		// tag is the tag for the reference
 		tag string
 		// digest is the digest for the reference (enforces digest reference)
@@ -44,37 +44,37 @@ func TestReferenceParse(t *testing.T) {
 		},
 		{
 			input:      "test.com/repo:tag",
-			hostname:   "test.com",
+			domain:     "test.com",
 			repository: "test.com/repo",
 			tag:        "tag",
 		},
 		{
 			input:      "test:5000/repo",
-			hostname:   "test:5000",
+			domain:     "test:5000",
 			repository: "test:5000/repo",
 		},
 		{
 			input:      "test:5000/repo:tag",
-			hostname:   "test:5000",
+			domain:     "test:5000",
 			repository: "test:5000/repo",
 			tag:        "tag",
 		},
 		{
 			input:      "test:5000/repo@sha256:ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff",
-			hostname:   "test:5000",
+			domain:     "test:5000",
 			repository: "test:5000/repo",
 			digest:     "sha256:ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff",
 		},
 		{
 			input:      "test:5000/repo:tag@sha256:ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff",
-			hostname:   "test:5000",
+			domain:     "test:5000",
 			repository: "test:5000/repo",
 			tag:        "tag",
 			digest:     "sha256:ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff",
 		},
 		{
 			input:      "test:5000/repo",
-			hostname:   "test:5000",
+			domain:     "test:5000",
 			repository: "test:5000/repo",
 		},
 		{
@@ -122,7 +122,7 @@ func TestReferenceParse(t *testing.T) {
 		},
 		{
 			input:      strings.Repeat("a/", 127) + "a:tag-puts-this-over-max",
-			hostname:   "a",
+			domain:     "a",
 			repository: strings.Repeat("a/", 127) + "a",
 			tag:        "tag-puts-this-over-max",
 		},
@@ -132,30 +132,30 @@ func TestReferenceParse(t *testing.T) {
 		},
 		{
 			input:      "sub-dom1.foo.com/bar/baz/quux",
-			hostname:   "sub-dom1.foo.com",
+			domain:     "sub-dom1.foo.com",
 			repository: "sub-dom1.foo.com/bar/baz/quux",
 		},
 		{
 			input:      "sub-dom1.foo.com/bar/baz/quux:some-long-tag",
-			hostname:   "sub-dom1.foo.com",
+			domain:     "sub-dom1.foo.com",
 			repository: "sub-dom1.foo.com/bar/baz/quux",
 			tag:        "some-long-tag",
 		},
 		{
 			input:      "b.gcr.io/test.example.com/my-app:test.example.com",
-			hostname:   "b.gcr.io",
+			domain:     "b.gcr.io",
 			repository: "b.gcr.io/test.example.com/my-app",
 			tag:        "test.example.com",
 		},
 		{
 			input:      "xn--n3h.com/myimage:xn--n3h.com", // ☃.com in punycode
-			hostname:   "xn--n3h.com",
+			domain:     "xn--n3h.com",
 			repository: "xn--n3h.com/myimage",
 			tag:        "xn--n3h.com",
 		},
 		{
 			input:      "xn--7o8h.com/myimage:xn--7o8h.com@sha512:ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", // 🐳.com in punycode
-			hostname:   "xn--7o8h.com",
+			domain:     "xn--7o8h.com",
 			repository: "xn--7o8h.com/myimage",
 			tag:        "xn--7o8h.com",
 			digest:     "sha512:ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff",
@@ -167,7 +167,7 @@ func TestReferenceParse(t *testing.T) {
 		},
 		{
 			input:      "foo/foo_bar.com:8080",
-			hostname:   "foo",
+			domain:     "foo",
 			repository: "foo/foo_bar.com",
 			tag:        "8080",
 		},
@@ -198,11 +198,11 @@ func TestReferenceParse(t *testing.T) {
 			if named.Name() != testcase.repository {
 				failf("unexpected repository: got %q, expected %q", named.Name(), testcase.repository)
 			}
-			hostname, _ := SplitHostname(named)
-			if hostname != testcase.hostname {
-				failf("unexpected hostname: got %q, expected %q", hostname, testcase.hostname)
+			domain, _ := SplitHostname(named)
+			if domain != testcase.domain {
+				failf("unexpected domain: got %q, expected %q", domain, testcase.domain)
 			}
-		} else if testcase.repository != "" || testcase.hostname != "" {
+		} else if testcase.repository != "" || testcase.domain != "" {
 			failf("expected named type, got %T", repo)
 		}
 
@@ -282,39 +282,39 @@ func TestWithNameFailure(t *testing.T) {
 
 func TestSplitHostname(t *testing.T) {
 	testcases := []struct {
-		input    string
-		hostname string
-		name     string
+		input  string
+		domain string
+		name   string
 	}{
 		{
-			input:    "test.com/foo",
-			hostname: "test.com",
-			name:     "foo",
+			input:  "test.com/foo",
+			domain: "test.com",
+			name:   "foo",
 		},
 		{
-			input:    "test_com/foo",
-			hostname: "",
-			name:     "test_com/foo",
+			input:  "test_com/foo",
+			domain: "",
+			name:   "test_com/foo",
 		},
 		{
-			input:    "test:8080/foo",
-			hostname: "test:8080",
-			name:     "foo",
+			input:  "test:8080/foo",
+			domain: "test:8080",
+			name:   "foo",
 		},
 		{
-			input:    "test.com:8080/foo",
-			hostname: "test.com:8080",
-			name:     "foo",
+			input:  "test.com:8080/foo",
+			domain: "test.com:8080",
+			name:   "foo",
 		},
 		{
-			input:    "test-com:8080/foo",
-			hostname: "test-com:8080",
-			name:     "foo",
+			input:  "test-com:8080/foo",
+			domain: "test-com:8080",
+			name:   "foo",
 		},
 		{
-			input:    "xn--n3h.com:18080/foo",
-			hostname: "xn--n3h.com:18080",
-			name:     "foo",
+			input:  "xn--n3h.com:18080/foo",
+			domain: "xn--n3h.com:18080",
+			name:   "foo",
 		},
 	}
 	for _, testcase := range testcases {
@@ -327,9 +327,9 @@ func TestSplitHostname(t *testing.T) {
 		if err != nil {
 			failf("error parsing name: %s", err)
 		}
-		hostname, name := SplitHostname(named)
-		if hostname != testcase.hostname {
-			failf("unexpected hostname: got %q, expected %q", hostname, testcase.hostname)
+		domain, name := SplitHostname(named)
+		if domain != testcase.domain {
+			failf("unexpected domain: got %q, expected %q", domain, testcase.domain)
 		}
 		if name != testcase.name {
 			failf("unexpected name: got %q, expected %q", name, testcase.name)
diff --git a/reference/regexp.go b/reference/regexp.go
index 9a7d366bc..405e995db 100644
--- a/reference/regexp.go
+++ b/reference/regexp.go
@@ -19,18 +19,18 @@ var (
 		alphaNumericRegexp,
 		optional(repeated(separatorRegexp, alphaNumericRegexp)))
 
-	// hostnameComponentRegexp restricts the registry hostname component of a
-	// repository name to start with a component as defined by hostnameRegexp
+	// domainComponentRegexp restricts the registry domain component of a
+	// repository name to start with a component as defined by domainRegexp
 	// and followed by an optional port.
-	hostnameComponentRegexp = match(`(?:[a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9-]*[a-zA-Z0-9])`)
+	domainComponentRegexp = match(`(?:[a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9-]*[a-zA-Z0-9])`)
 
-	// hostnameRegexp defines the structure of potential hostname components
+	// domainRegexp defines the structure of potential domain components
 	// that may be part of image names. This is purposely a subset of what is
 	// allowed by DNS to ensure backwards compatibility with Docker image
 	// names.
-	hostnameRegexp = expression(
-		hostnameComponentRegexp,
-		optional(repeated(literal(`.`), hostnameComponentRegexp)),
+	domainRegexp = expression(
+		domainComponentRegexp,
+		optional(repeated(literal(`.`), domainComponentRegexp)),
 		optional(literal(`:`), match(`[0-9]+`)))
 
 	// TagRegexp matches valid tag names. From docker/docker:graph/tags.go.
@@ -48,17 +48,17 @@ var (
 	anchoredDigestRegexp = anchored(DigestRegexp)
 
 	// NameRegexp is the format for the name component of references. The
-	// regexp has capturing groups for the hostname and name part omitting
+	// regexp has capturing groups for the domain and name part omitting
 	// the separating forward slash from either.
 	NameRegexp = expression(
-		optional(hostnameRegexp, literal(`/`)),
+		optional(domainRegexp, literal(`/`)),
 		nameComponentRegexp,
 		optional(repeated(literal(`/`), nameComponentRegexp)))
 
 	// anchoredNameRegexp is used to parse a name value, capturing the
-	// hostname and trailing components.
+	// domain and trailing components.
 	anchoredNameRegexp = anchored(
-		optional(capture(hostnameRegexp), literal(`/`)),
+		optional(capture(domainRegexp), literal(`/`)),
 		capture(nameComponentRegexp,
 			optional(repeated(literal(`/`), nameComponentRegexp))))
 
@@ -68,6 +68,25 @@ var (
 	ReferenceRegexp = anchored(capture(NameRegexp),
 		optional(literal(":"), capture(TagRegexp)),
 		optional(literal("@"), capture(DigestRegexp)))
+
+	// IdentifierRegexp is the format for string identifier used as a
+	// content addressable identifier using sha256. These identifiers
+	// are like digests without the algorithm, since sha256 is used.
+	IdentifierRegexp = match(`([a-f0-9]{64})`)
+
+	// ShortIdentifierRegexp is the format used to represent a prefix
+	// of an identifier. A prefix may be used to match a sha256 identifier
+	// within a list of trusted identifiers.
+	ShortIdentifierRegexp = match(`([a-f0-9]{6,64})`)
+
+	// anchoredIdentifierRegexp is used to check or match an
+	// identifier value, anchored at start and end of string.
+	anchoredIdentifierRegexp = anchored(IdentifierRegexp)
+
+	// anchoredShortIdentifierRegexp is used to check if a value
+	// is a possible identifier prefix, anchored at start and end
+	// of string.
+	anchoredShortIdentifierRegexp = anchored(ShortIdentifierRegexp)
 )
 
 // match compiles the string to a regular expression.
diff --git a/reference/regexp_test.go b/reference/regexp_test.go
index 2ec39377a..c21263992 100644
--- a/reference/regexp_test.go
+++ b/reference/regexp_test.go
@@ -33,7 +33,7 @@ func checkRegexp(t *testing.T, r *regexp.Regexp, m regexpMatch) {
 	}
 }
 
-func TestHostRegexp(t *testing.T) {
+func TestDomainRegexp(t *testing.T) {
 	hostcases := []regexpMatch{
 		{
 			input: "test.com",
@@ -116,7 +116,7 @@ func TestHostRegexp(t *testing.T) {
 			match: true,
 		},
 	}
-	r := regexp.MustCompile(`^` + hostnameRegexp.String() + `$`)
+	r := regexp.MustCompile(`^` + domainRegexp.String() + `$`)
 	for i := range hostcases {
 		checkRegexp(t, r, hostcases[i])
 	}
@@ -487,3 +487,67 @@ func TestReferenceRegexp(t *testing.T) {
 	}
 
 }
+
+func TestIdentifierRegexp(t *testing.T) {
+	fullCases := []regexpMatch{
+		{
+			input: "da304e823d8ca2b9d863a3c897baeb852ba21ea9a9f1414736394ae7fcaf9821",
+			match: true,
+		},
+		{
+			input: "7EC43B381E5AEFE6E04EFB0B3F0693FF2A4A50652D64AEC573905F2DB5889A1C",
+			match: false,
+		},
+		{
+			input: "da304e823d8ca2b9d863a3c897baeb852ba21ea9a9f1414736394ae7fcaf",
+			match: false,
+		},
+		{
+			input: "sha256:da304e823d8ca2b9d863a3c897baeb852ba21ea9a9f1414736394ae7fcaf9821",
+			match: false,
+		},
+		{
+			input: "da304e823d8ca2b9d863a3c897baeb852ba21ea9a9f1414736394ae7fcaf98218482",
+			match: false,
+		},
+	}
+
+	shortCases := []regexpMatch{
+		{
+			input: "da304e823d8ca2b9d863a3c897baeb852ba21ea9a9f1414736394ae7fcaf9821",
+			match: true,
+		},
+		{
+			input: "7EC43B381E5AEFE6E04EFB0B3F0693FF2A4A50652D64AEC573905F2DB5889A1C",
+			match: false,
+		},
+		{
+			input: "da304e823d8ca2b9d863a3c897baeb852ba21ea9a9f1414736394ae7fcaf",
+			match: true,
+		},
+		{
+			input: "sha256:da304e823d8ca2b9d863a3c897baeb852ba21ea9a9f1414736394ae7fcaf9821",
+			match: false,
+		},
+		{
+			input: "da304e823d8ca2b9d863a3c897baeb852ba21ea9a9f1414736394ae7fcaf98218482",
+			match: false,
+		},
+		{
+			input: "da304",
+			match: false,
+		},
+		{
+			input: "da304e",
+			match: true,
+		},
+	}
+
+	for i := range fullCases {
+		checkRegexp(t, anchoredIdentifierRegexp, fullCases[i])
+	}
+
+	for i := range shortCases {
+		checkRegexp(t, anchoredShortIdentifierRegexp, shortCases[i])
+	}
+}