diff --git a/capsule/format3_test.go b/capsule/format3_test.go
index 9d5c945..e6d917d 100644
--- a/capsule/format3_test.go
+++ b/capsule/format3_test.go
@@ -135,7 +135,7 @@ func TestSecurityVerdicts(t *testing.T) {
 
 func sampleHead() *capsule.Head {
 	h := &capsule.Head{
-		Comment: "Para ti ❤️",
+		Comment: "Para ti ❤\ufe0f",
 		Author:  "Ana López",
 		Files: []capsule.File{
 			{Path: "fotos/playa.jpg", Size: 10, Start: 0, End: 10, MTime: 1759190400, HasMTime: true},
@@ -240,19 +240,19 @@ func TestDecodeHeadLayers(t *testing.T) {
 		"an unknown key 8":         {head(t, map[uint64]any{8: uint64(1)}), datekeys.ErrNonCanonicalCBOR},
 		"a byte more":              {append(head(t, nil), 0), datekeys.ErrNonCanonicalCBOR},
 		// Layer 4, in key order.
-		"a comment with U+202E":               {head(t, map[uint64]any{3: "a‮b"}), datekeys.ErrHeadInvalid},
+		"a comment with U+202E":               {head(t, map[uint64]any{3: "a\u202eb"}), datekeys.ErrHeadInvalid},
 		"a comment with the tag U+E0041":      {head(t, map[uint64]any{3: "a\U000E0041"}), datekeys.ErrHeadInvalid},
 		"an author with LF":                   {head(t, map[uint64]any{4: "a\nb"}), datekeys.ErrHeadInvalid},
 		"R3: ..":                              {head(t, map[uint64]any{5: []any{file("..", 0, 0, 0)}}), datekeys.ErrHeadInvalid},
 		"R2: /a":                              {head(t, map[uint64]any{5: []any{file("/a", 0, 0, 0)}}), datekeys.ErrHeadInvalid},
-		"R4b: a and VS16":                     {head(t, map[uint64]any{5: []any{file("a️", 0, 0, 0)}}), datekeys.ErrHeadInvalid},
+		"R4b: a and VS16":                     {head(t, map[uint64]any{5: []any{file("a\ufe0f", 0, 0, 0)}}), datekeys.ErrHeadInvalid},
 		"R6: CON.txt":                         {head(t, map[uint64]any{5: []any{file("CON.txt", 0, 0, 0)}}), datekeys.ErrHeadInvalid},
 		"R10: .datekeys-x":                    {head(t, map[uint64]any{5: []any{file(".datekeys-x", 0, 0, 0)}}), datekeys.ErrHeadInvalid},
 		"layout: a first start that is not 0": {head(t, map[uint64]any{5: []any{file("a", 1, 1, 2)}}), datekeys.ErrHeadInvalid},
 		"layout: end minus start is not size": {head(t, map[uint64]any{5: []any{file("a", 2, 0, 1)}}), datekeys.ErrHeadInvalid},
 		"layout: a gap":                       {head(t, map[uint64]any{5: []any{file("a", 1, 0, 1), file("b", 1, 2, 3)}}), datekeys.ErrHeadInvalid},
 		"R7: A.txt and a.txt":                 {head(t, map[uint64]any{5: []any{file("A.txt", 0, 0, 0), file("a.txt", 0, 0, 0)}}), datekeys.ErrHeadInvalid},
-		"a comment and a path that break":     {head(t, map[uint64]any{3: "a‮", 5: []any{file("..", 0, 0, 0)}}), datekeys.ErrHeadInvalid},
+		"a comment and a path that break":     {head(t, map[uint64]any{3: "a\u202e", 5: []any{file("..", 0, 0, 0)}}), datekeys.ErrHeadInvalid},
 		"a path that breaks, then an unknown critical extension": {head(t, map[uint64]any{5: []any{file("..", 0, 0, 0)}, 6: []any{map[uint64]any{0: "x.example", 1: uint64(1)}}}), datekeys.ErrHeadInvalid},
 		"an unknown critical extension":                          {head(t, map[uint64]any{6: []any{map[uint64]any{0: "x.example", 1: uint64(1)}}}), datekeys.ErrExtensionCriticalUnknown},
 	} {
@@ -269,10 +269,10 @@ func TestDecodeHeadLayers(t *testing.T) {
 	}
 }
 
-// codes counts the normative errors err wraps, ERR_HEAD_INVALID included.
+// codes counts the normative errors err wraps.
 func codes(err error) int {
 	n := 0
-	for _, e := range append(datekeys.All(), datekeys.ErrHeadInvalid) {
+	for _, e := range datekeys.All() {
 		if errors.Is(err, e) {
 			n++
 		}
diff --git a/capsule/open3_test.go b/capsule/open3_test.go
index d87e05a..90a90bc 100644
--- a/capsule/open3_test.go
+++ b/capsule/open3_test.go
@@ -110,7 +110,7 @@ func TestOpen3(t *testing.T) {
 	c := capsule3{
 		paths:    []string{"fotos/playa.jpg", "nota.txt", "vacío.txt"},
 		contents: [][]byte{photo, []byte("Hola.\n"), {}},
-		comment:  "Para ti ❤️", author: "Ana López",
+		comment:  "Para ti ❤\ufe0f", author: "Ana López",
 	}
 	dkc, body := c.build(t)
 
diff --git a/errors.go b/errors.go
index 700be02..e2eddc7 100644
--- a/errors.go
+++ b/errors.go
@@ -73,8 +73,7 @@ var (
 	ErrExtensionDataInvalid = &Error{"ERR_EXTENSION_DATA_INVALID"}
 	// ErrHeadInvalid: the head of a format 3 capsule is well encoded but one
 	// of its fields breaks its rules: a path, the comment, the declared author
-	// or the layout of the files (spec §29.4 to §29.6). New in v0.10; All
-	// lists it once SpecVersion is 0.10.
+	// or the layout of the files (spec §29.4 to §29.6). New in v0.10.
 	ErrHeadInvalid = &Error{"ERR_HEAD_INVALID"}
 )
 
@@ -85,7 +84,7 @@ func All() []*Error {
 		ErrUnknownProfile, ErrProfileMismatch, ErrDateKeyInvalid, ErrDateKeyNonCanonical,
 		ErrRoundMismatch, ErrReleaseUnavailable, ErrReleaseInvalid, ErrAccessRequired,
 		ErrAccessInvalid, ErrPolicyStructureMismatch, ErrHeaderBinding, ErrIntegrity,
-		ErrExtensionCriticalUnknown, ErrExtensionDataInvalid,
+		ErrExtensionCriticalUnknown, ErrExtensionDataInvalid, ErrHeadInvalid,
 	}
 }
 
diff --git a/internal/pathrule/pathrule_test.go b/internal/pathrule/pathrule_test.go
index 5c929c2..8fe7e6a 100644
--- a/internal/pathrule/pathrule_test.go
+++ b/internal/pathrule/pathrule_test.go
@@ -46,15 +46,15 @@ func TestProperties(t *testing.T) {
 
 func TestNFD(t *testing.T) {
 	for _, c := range []struct{ in, want string }{
-		{"é", "é"},
-		{"Å", "Å"},    // ANGSTROM SIGN, a singleton decomposition
-		{"K", "K"},     // KELVIN SIGN
-		{"한", "한"},   // Hangul, with a final jamo
-		{"하", "하"},    // Hangul, without
-		{"ạ́", "ạ́"}, // canonical order
-		{"ΐ", "ΐ"},
-		{"ǖ", "ǖ"},     // recursive decomposition
-		{"á‍̣", "á‍̣"}, // ZWJ is a starter
+		{"é", "e\u0301"},
+		{"\u212b", "A\u030a"},              // ANGSTROM SIGN, a singleton decomposition
+		{"\u212a", "K"},                    // KELVIN SIGN
+		{"한", "한"},                       // Hangul, with a final jamo
+		{"하", "하"},                        // Hangul, without
+		{"a\u0301\u0323", "a\u0323\u0301"}, // canonical order
+		{"ΐ", "ι\u0308\u0301"},
+		{"ǖ", "u\u0308\u0304"},                         // recursive decomposition
+		{"a\u0301\u200d\u0323", "a\u0301\u200d\u0323"}, // ZWJ is a starter
 	} {
 		if got := NFD(c.in); got != c.want {
 			t.Errorf("NFD(%+q) = %+q, want %+q", c.in, got, c.want)
@@ -66,11 +66,11 @@ func TestKey(t *testing.T) {
 	for _, same := range [][2]string{
 		{"A.txt", "a.txt"},
 		{"Straße", "STRASSE"},
-		{"K", "k"},
+		{"\u212a", "k"},
 		{"ı", "i"},
-		{"é", "é"},
-		{"ab", "a‌b"},
-		{"á‍̣", "ạ́"},
+		{"é", "e\u0301"},
+		{"ab", "a\u200cb"},
+		{"a\u0301\u200d\u0323", "a\u0323\u0301"},
 		{".DateKeys-x", ".datekeys-x"},
 	} {
 		if Key(same[0]) != Key(same[1]) {
@@ -96,9 +96,9 @@ func rule(err error) string {
 
 func TestCheckPath(t *testing.T) {
 	const (
-		zwj  = "‍"
-		zwnj = "‌"
-		vs16 = "️"
+		zwj  = "\u200d"
+		zwnj = "\u200c"
+		vs16 = "\ufe0f"
 	)
 	scotland := "\U0001F3F4\U000E0067\U000E0062\U000E0073\U000E0063\U000E0074\U000E007F"
 	for _, c := range []struct {
@@ -111,7 +111,7 @@ func TestCheckPath(t *testing.T) {
 		{"Para ti ♥.jpg", ""},                          // bestfit874 maps ♥ to 0x03
 		{"§ 3 contrato.pdf", ""},                       // bestfit874 maps § to 0x15
 		{"Madrid → Lisboa", ""},                        // bestfit1253 maps → to '>'
-		{"❤" + vs16 + ".txt", ""},                      // ❤️
+		{"❤" + vs16 + ".txt", ""},                      // ❤\ufe0f
 		{"\U0001F3F3" + vs16 + zwj + "\U0001F308", ""}, // rainbow flag
 		{"\U0001F468" + zwj + "\U0001F469" + zwj + "\U0001F467", ""},
 		{"ab" + zwnj + "c", ""},
@@ -121,7 +121,7 @@ func TestCheckPath(t *testing.T) {
 		{"report~2023.txt", ""},
 		{strings.Repeat("a", 255), ""},
 		{strings.Repeat("ΐ", 85), ""}, // 170 bytes, 255 UTF-16 units after NFD
-		{" a ", ""},                   // no table maps U+00A0 to U+0020... checked below
+		{"\u00a0a\u00a0", ""},         // no table maps U+00A0 to U+0020... checked below
 
 		// R2.
 		{"/a", "R2"},
@@ -139,13 +139,13 @@ func TestCheckPath(t *testing.T) {
 		{"a\\b", "R4"},
 		{"a?b", "R4"},
 		{"a\tb", "R4"},
-		{"a
b", "R4"},
-		{"a­b", "R4"},
-		{"ab", "R4"},
-		{"a‮b", "R4"},
-		{"informeanexo", "R4"},
-		{"a͸b", "R4"},
-		{"a￾b", "R4"},
+		{"a\u2028b", "R4"},
+		{"a\u00adb", "R4"},
+		{"a\u206ab", "R4"},
+		{"a\u202eb", "R4"},
+		{"informe\uf03aanexo", "R4"},
+		{"a\u0378b", "R4"},
+		{"a\ufffeb", "R4"},
 		{scotland, "R4"},
 		{"\U0001F600\U000E0100", "R4"}, // VS17
 		// R4b.
@@ -174,7 +174,7 @@ func TestCheckPath(t *testing.T) {
 		{"ＣＯＮ.txt", "R6c"}, // full-width CON
 		{"a∖b", "R6c"},     // SET MINUS
 		{"a∶b", "R6c"},     // RATIO
-		{"　a", "R6c"},      // bestfit1252 maps U+3000 to U+0020, which breaks R5
+		{"\u3000a", "R6c"}, // bestfit1252 maps U+3000 to U+0020, which breaks R5
 		{"a／b", "R6c"},     // full-width solidus
 		{"．．", "R6c"},      // full-width dots project to ".."
 		// R10.
@@ -189,7 +189,7 @@ func TestCheckPath(t *testing.T) {
 			}
 			continue
 		}
-		if c.path == " a " {
+		if c.path == "\u00a0a\u00a0" {
 			// Whatever the tables give, it must be R6c or nothing (R5 is
 			// about U+0020 only).
 			if got != "" && got != "R6c" {
@@ -214,8 +214,8 @@ func TestCheckTree(t *testing.T) {
 		{[]string{"a/b", "a/b/c"}, "R7"},
 		{[]string{"Fotos/b", "fotos/a"}, "R7"},
 		{[]string{"STRASSE", "Straße"}, "R7"},
-		{[]string{"ab", "a‌b"}, "R7"},
-		{[]string{"k", "K"}, "R7"},
+		{[]string{"ab", "a\u200cb"}, "R7"},
+		{[]string{"k", "\u212a"}, "R7"},
 	} {
 		if got := rule(CheckTree(c.paths)); got != c.rule {
 			t.Errorf("CheckTree(%+q): %s, want %s", c.paths, got, c.rule)
@@ -240,22 +240,22 @@ func TestTexts(t *testing.T) {
 		rule    string
 	}{
 		{"Hola\tmundo\nsegunda línea", true, ""},
-		{"❤️ para ti", true, ""},
+		{"❤\ufe0f para ti", true, ""},
 		{"Hola\r\n", true, "text"},
-		{"a‮b", true, "text"},
+		{"a\u202eb", true, "text"},
 		{"Hola\U000E0049\U000E0047", true, "text"}, // tag characters
 		{"\U0001F600\U000E0100", true, "text"},     // VS17
-		{"a️", true, "text"},                       // VS16 after a letter
-		{"a‍\nb", true, "text"},                    // ZWJ at the end of a line
-		{"a￾", true, "text"},
-		{"a﷐", true, "text"},
-		{"a­b", true, "text"},
+		{"a\ufe0f", true, "text"},                  // VS16 after a letter
+		{"a\u200d\nb", true, "text"},               // ZWJ at the end of a line
+		{"a\ufffe", true, "text"},
+		{"a\ufdd0", true, "text"},
+		{"a\u00adb", true, "text"},
 		{"Ana López", false, ""},
 		{"Ana\tLópez", false, "text"},
 		{"Ana\nLópez", false, "text"},
 		{" Ana", false, "text"},
 		{"Ana ", false, "text"},
-		{"a‎b", false, "text"},
+		{"a\u200eb", false, "text"},
 	} {
 		check := CheckAuthor
 		if c.comment {
diff --git a/testdata/fixtures/empty_payload.json b/testdata/fixtures/empty_payload.json
index 58d642a..3899f77 100644
--- a/testdata/fixtures/empty_payload.json
+++ b/testdata/fixtures/empty_payload.json
@@ -1,6 +1,6 @@
 {
   "description": "time_only capsule with an empty payload",
-  "spec": "0.9",
+  "spec": "0.10",
   "format": 1,
   "file": "empty_payload.dkc",
   "sha256": "871e9bf05b52bbae17f3adfbbf97b46e7f0e53aa8f57bcaa506e43f36f53a9d4",
diff --git a/testdata/fixtures/format2_empty_payload.json b/testdata/fixtures/format2_empty_payload.json
index 00542b4..8fdf39f 100644
--- a/testdata/fixtures/format2_empty_payload.json
+++ b/testdata/fixtures/format2_empty_payload.json
@@ -1,6 +1,6 @@
 {
   "description": "format 2 time_only capsule with an empty content: L = 0, P = 256",
-  "spec": "0.9",
+  "spec": "0.10",
   "format": 2,
   "file": "format2_empty_payload.dkc",
   "sha256": "7aea2b5aa48b1a46053716f733d50fab9cd0b80b1be67631bcc06c5bb765dc21",
diff --git a/testdata/fixtures/format2_time_and_key_portable.dkk.json b/testdata/fixtures/format2_time_and_key_portable.dkk.json
index ef27ab7..79fcb68 100644
--- a/testdata/fixtures/format2_time_and_key_portable.dkk.json
+++ b/testdata/fixtures/format2_time_and_key_portable.dkk.json
@@ -1,6 +1,6 @@
 {
   "description": "portable X25519 .dkk of format2_time_and_key_portable.dkc",
-  "spec": "0.9",
+  "spec": "0.10",
   "file": "format2_time_and_key_portable.dkk",
   "sha256": "095b7bc516a22bf0c2366f0af3cd48bfe857a2354d6e2a9b285278b95e450fe0",
   "credential_id": "e3c7be83cbf1fbd6b115c96411b3bd01",
diff --git a/testdata/fixtures/format2_time_and_key_portable.json b/testdata/fixtures/format2_time_and_key_portable.json
index 2e3a854..48599df 100644
--- a/testdata/fixtures/format2_time_and_key_portable.json
+++ b/testdata/fixtures/format2_time_and_key_portable.json
@@ -1,6 +1,6 @@
 {
   "description": "format 2 time_and_key capsule with one credential, a portable .dkk, and 15 dummies",
-  "spec": "0.9",
+  "spec": "0.10",
   "format": 2,
   "file": "format2_time_and_key_portable.dkc",
   "sha256": "600892659fe4890223e895876275f656995d170fda42b07fb2bec0ca51ce4b43",
diff --git a/testdata/fixtures/format2_time_and_key_recipients.dkk.json b/testdata/fixtures/format2_time_and_key_recipients.dkk.json
index 7c18f05..5cd0a66 100644
--- a/testdata/fixtures/format2_time_and_key_recipients.dkk.json
+++ b/testdata/fixtures/format2_time_and_key_recipients.dkk.json
@@ -1,6 +1,6 @@
 {
   "description": "portable X25519 .dkk of format2_time_and_key_recipients.dkc",
-  "spec": "0.9",
+  "spec": "0.10",
   "file": "format2_time_and_key_recipients.dkk",
   "sha256": "2ad99b1556086ec311d7f0b3bd3aaba05e75f45c4fa22490b0d5e8bb0b1a222e",
   "credential_id": "93cedf68421710e83908ec683b104436",
diff --git a/testdata/fixtures/format2_time_and_key_recipients.json b/testdata/fixtures/format2_time_and_key_recipients.json
index a68df1b..d453028 100644
--- a/testdata/fixtures/format2_time_and_key_recipients.json
+++ b/testdata/fixtures/format2_time_and_key_recipients.json
@@ -1,6 +1,6 @@
 {
   "description": "format 2 time_and_key capsule for three known X25519 recipients and a portable .dkk, and 12 dummies",
-  "spec": "0.9",
+  "spec": "0.10",
   "format": 2,
   "file": "format2_time_and_key_recipients.dkc",
   "sha256": "1a44fd8708c92e2e0a10cfcb1d864a71331ea9af25d97e1a42e969dc898959e3",
diff --git a/testdata/fixtures/format2_time_and_key_sixteen.json b/testdata/fixtures/format2_time_and_key_sixteen.json
index e527407..4cbd5c5 100644
--- a/testdata/fixtures/format2_time_and_key_sixteen.json
+++ b/testdata/fixtures/format2_time_and_key_sixteen.json
@@ -1,6 +1,6 @@
 {
   "description": "format 2 time_and_key capsule for sixteen known X25519 recipients, without dummies",
-  "spec": "0.9",
+  "spec": "0.10",
   "format": 2,
   "file": "format2_time_and_key_sixteen.dkc",
   "sha256": "7aaac5c18f216bf53df326ecc817179640a53408cf25dfd50488910a762dc381",
diff --git a/testdata/fixtures/format2_time_only.json b/testdata/fixtures/format2_time_only.json
index 0362945..b653845 100644
--- a/testdata/fixtures/format2_time_only.json
+++ b/testdata/fixtures/format2_time_only.json
@@ -1,6 +1,6 @@
 {
   "description": "format 2 time_only capsule, padding code 2 (reforzado): L = 78000, P = 79872, two STREAM chunks",
-  "spec": "0.9",
+  "spec": "0.10",
   "format": 2,
   "file": "format2_time_only.dkc",
   "sha256": "f5a40ac6b8a08a0c12db6114c2bca23522d6a77b512b509a217fb15f367813c4",
diff --git a/testdata/fixtures/format2_time_only_bloque256.json b/testdata/fixtures/format2_time_only_bloque256.json
index a833982..e8ffc84 100644
--- a/testdata/fixtures/format2_time_only_bloque256.json
+++ b/testdata/fixtures/format2_time_only_bloque256.json
@@ -1,6 +1,6 @@
 {
   "description": "format 2 time_only capsule with the content of format2_time_only and padding code 1 (bloque256): L = 78000, P = 78080",
-  "spec": "0.9",
+  "spec": "0.10",
   "format": 2,
   "file": "format2_time_only_bloque256.dkc",
   "sha256": "aae769c30d04920801d8b293d30864fbe223c9c9353ec2b4907a1ee1996e39f9",
diff --git a/testdata/fixtures/format2_time_only_extensions.json b/testdata/fixtures/format2_time_only_extensions.json
index ff86da8..2bba812 100644
--- a/testdata/fixtures/format2_time_only_extensions.json
+++ b/testdata/fixtures/format2_time_only_extensions.json
@@ -1,6 +1,6 @@
 {
   "description": "format 2 time_only capsule with a noncritical PUBLIC_HEADER extension and a noncritical CONTROL_CBOR extension",
-  "spec": "0.9",
+  "spec": "0.10",
   "format": 2,
   "file": "format2_time_only_extensions.dkc",
   "sha256": "fb406100d5703a2e888983b3175ed34a09a34469cc722256e5cf535dd728fbe9",
diff --git a/testdata/fixtures/time_and_key_portable.dkk.json b/testdata/fixtures/time_and_key_portable.dkk.json
index 1b04553..4a2ff4d 100644
--- a/testdata/fixtures/time_and_key_portable.dkk.json
+++ b/testdata/fixtures/time_and_key_portable.dkk.json
@@ -1,6 +1,6 @@
 {
   "description": "portable X25519 .dkk of time_and_key_portable.dkc",
-  "spec": "0.9",
+  "spec": "0.10",
   "file": "time_and_key_portable.dkk",
   "sha256": "e528fa2c832c91119f0684bb9d6fb3c4c2d0d55183482890e7c4fe92f668426a",
   "credential_id": "3955e944a3c60cfa1fd6485e9693c77d",
diff --git a/testdata/fixtures/time_and_key_portable.json b/testdata/fixtures/time_and_key_portable.json
index 398d045..d57efe6 100644
--- a/testdata/fixtures/time_and_key_portable.json
+++ b/testdata/fixtures/time_and_key_portable.json
@@ -1,6 +1,6 @@
 {
   "description": "time_and_key capsule whose only recipient is a portable .dkk",
-  "spec": "0.9",
+  "spec": "0.10",
   "format": 1,
   "file": "time_and_key_portable.dkc",
   "sha256": "2e97878078bae6358037a9c264f379a3cbe839f767d69836b0343f35657b2972",
diff --git a/testdata/fixtures/time_and_key_portable_extension.dkk.json b/testdata/fixtures/time_and_key_portable_extension.dkk.json
index 8abce2e..1ed6121 100644
--- a/testdata/fixtures/time_and_key_portable_extension.dkk.json
+++ b/testdata/fixtures/time_and_key_portable_extension.dkk.json
@@ -1,6 +1,6 @@
 {
   "description": "portable X25519 .dkk of time_and_key_portable.dkc with a noncritical extension: the credential of time_and_key_portable.dkk re-issued with org.example.delivery",
-  "spec": "0.9",
+  "spec": "0.10",
   "file": "time_and_key_portable_extension.dkk",
   "sha256": "0bf463a7c65627b7dda2234d728df89ec5b835816a2a37b91497d8fecc5ea548",
   "credential_id": "3955e944a3c60cfa1fd6485e9693c77d",
diff --git a/testdata/fixtures/time_and_key_recipients.dkk.json b/testdata/fixtures/time_and_key_recipients.dkk.json
index 49dfa34..4fd9722 100644
--- a/testdata/fixtures/time_and_key_recipients.dkk.json
+++ b/testdata/fixtures/time_and_key_recipients.dkk.json
@@ -1,6 +1,6 @@
 {
   "description": "portable X25519 .dkk of time_and_key_recipients.dkc",
-  "spec": "0.9",
+  "spec": "0.10",
   "file": "time_and_key_recipients.dkk",
   "sha256": "19f6c47150c3194712d454f43c7392b7344e6b4e7b074d83e9ca5f563a8e072f",
   "credential_id": "b89292aedf6d05d584cec9a871ce8735",
diff --git a/testdata/fixtures/time_and_key_recipients.json b/testdata/fixtures/time_and_key_recipients.json
index a20b83d..1ea76ed 100644
--- a/testdata/fixtures/time_and_key_recipients.json
+++ b/testdata/fixtures/time_and_key_recipients.json
@@ -1,6 +1,6 @@
 {
   "description": "time_and_key capsule for two known X25519 recipients and a portable .dkk",
-  "spec": "0.9",
+  "spec": "0.10",
   "format": 1,
   "file": "time_and_key_recipients.dkc",
   "sha256": "69ac110380f5d768b5b6afaa157a50ed17d8ceccfbd4604ffa5b6da38539b635",
diff --git a/testdata/fixtures/time_only.json b/testdata/fixtures/time_only.json
index 0e546c1..dc11d03 100644
--- a/testdata/fixtures/time_only.json
+++ b/testdata/fixtures/time_only.json
@@ -1,6 +1,6 @@
 {
   "description": "time_only capsule, two STREAM chunks, no extensions",
-  "spec": "0.9",
+  "spec": "0.10",
   "format": 1,
   "file": "time_only.dkc",
   "sha256": "99e915810d595f1092700b728f5e5081d78efe83f5343e76325b1bcc2c33ccf2",
diff --git a/testdata/fixtures/time_only_extensions.json b/testdata/fixtures/time_only_extensions.json
index 55d5cfe..10fddeb 100644
--- a/testdata/fixtures/time_only_extensions.json
+++ b/testdata/fixtures/time_only_extensions.json
@@ -1,6 +1,6 @@
 {
   "description": "time_only capsule with a noncritical PUBLIC_HEADER extension and a noncritical CONTROL_CBOR extension",
-  "spec": "0.9",
+  "spec": "0.10",
   "format": 1,
   "file": "time_only_extensions.dkc",
   "sha256": "0446c9b73e267adcb24e5cc89afba2544a386ec9a050016e06517a4a57aa2085",
diff --git a/testdata/vectors/cbor.json b/testdata/vectors/cbor.json
index 4bd3fd8..151d729 100644
--- a/testdata/vectors/cbor.json
+++ b/testdata/vectors/cbor.json
@@ -1,5 +1,5 @@
 {
-  "spec": "0.9",
+  "spec": "0.10",
   "description": "CBOR profile of spec §58 and the schemas of spec/datekeys.cddl, generated by the reference implementation. accept and reject are walked as one data item of the profile with the limits of walk; schemas are decoded with the decoder of their schema. See testdata/README.md.",
   "walk": {
     "max_depth": 3,
diff --git a/testdata/vectors/dk1.json b/testdata/vectors/dk1.json
index f19ac20..e5ba4fc 100644
--- a/testdata/vectors/dk1.json
+++ b/testdata/vectors/dk1.json
@@ -1,5 +1,5 @@
 {
-  "spec": "0.9",
+  "spec": "0.10",
   "description": "Canonical dk1_ strings and rejected encodings (spec §18, §19, §66), generated by the reference implementation.",
   "vectors": [
     {
diff --git a/testdata/vectors/inspect_differential.json b/testdata/vectors/inspect_differential.json
index d470cfe..71a1658 100644
--- a/testdata/vectors/inspect_differential.json
+++ b/testdata/vectors/inspect_differential.json
@@ -1,5 +1,5 @@
 {
-  "spec": "0.9",
+  "spec": "0.10",
   "description": "Differential corpus of the pre-unlock checks (spec §63 steps 1 to 8): deterministic mutations of the official .dkc fixtures with the verdict of the reference implementation. See testdata/README.md.",
   "format": "Each mutation is bases[base].file (in testdata/fixtures) with its edits applied. An edit is [at, delete, insert]: the delete bytes at offset at of the base are replaced by the bytes of the hex string insert. The edits of one mutation refer to offsets of the unmodified base, are sorted by offset and do not overlap. result is the verdict of steps 1 to 8 of spec §63 (capsule.Inspect, the Quicknet profile pinned, no extension known, no network, no secret): ok, or the normative error code, with step the step that failed. kind names the generator of the mutation and is informative.",
   "seed": 20260925,
diff --git a/testdata/vectors/mutations.json b/testdata/vectors/mutations.json
index a232241..427ed24 100644
--- a/testdata/vectors/mutations.json
+++ b/testdata/vectors/mutations.json
@@ -1,5 +1,5 @@
 {
-  "spec": "0.9",
+  "spec": "0.10",
   "description": "Mutation corpus of spec §64 and further cases of capsule.TestMutationCorpus, generated by the reference implementation: each case is a .dkc and what the reader is given, with the normative error and the step of spec §63 at which capsule.Open fails. See testdata/README.md.",
   "cases": [
     {
diff --git a/testdata/vectors/padding.json b/testdata/vectors/padding.json
index 6d8b9ff..a982752 100644
--- a/testdata/vectors/padding.json
+++ b/testdata/vectors/padding.json
@@ -1,5 +1,5 @@
 {
-  "spec": "0.9",
+  "spec": "0.10",
   "description": "Padding rules of the payload of a format 2 capsule (spec §29.1): for each content length L, P with code 1 (bloque256) and code 2 (reforzado), and the length of PAYLOAD_AGE for each. e, s and last_bits are informative. Generated by the reference implementation. See testdata/README.md.",
   "l_max": 8936830510563328,
   "vectors": [
diff --git a/testdata/vectors/profile_quicknet.json b/testdata/vectors/profile_quicknet.json
index 009cd00..ff60352 100644
--- a/testdata/vectors/profile_quicknet.json
+++ b/testdata/vectors/profile_quicknet.json
@@ -1,5 +1,5 @@
 {
-  "spec": "0.9",
+  "spec": "0.10",
   "description": "Quicknet Provider Profile V1: exact Deterministic CBOR and profile_hash (spec §11, §12, §75 item 2), generated by the reference implementation.",
   "profile_id": "datekeys:quicknet:v1",
   "provider": "drand",
diff --git a/testdata/vectors/quicknet_rounds.json b/testdata/vectors/quicknet_rounds.json
index 44668f7..84d73f1 100644
--- a/testdata/vectors/quicknet_rounds.json
+++ b/testdata/vectors/quicknet_rounds.json
@@ -1,5 +1,5 @@
 {
-  "spec": "0.9",
+  "spec": "0.10",
   "profile": "datekeys:quicknet:v1",
   "description": "Quicknet date to round resolution (spec §15, §16, §65), generated by the reference implementation.",
   "vectors": [
diff --git a/testdata/vectors/tlock_ibe.json b/testdata/vectors/tlock_ibe.json
index 0dc31a7..a0aa127 100644
--- a/testdata/vectors/tlock_ibe.json
+++ b/testdata/vectors/tlock_ibe.json
@@ -1,5 +1,5 @@
 {
-  "spec": "0.9",
+  "spec": "0.10",
   "description": "H2 of the IBE-CCA of tlock (spec §63 step 11): SHA-256 of \"IBE-H2\" and the 576 bytes of an element of GT, c1 before c0 at every level of the tower and each coordinate of Fp in 48 bytes big-endian (the order of kilic/bls12-381), truncated to 16 bytes. Generated by the reference implementation with drand/kyber-bls12381, the pairing of tlock.",
   "vectors": [
     {
diff --git a/version.go b/version.go
index dc865b3..0badb0a 100644
--- a/version.go
+++ b/version.go
@@ -6,11 +6,11 @@ import (
 )
 
 // SpecVersion is the version of the DateKeys Protocol Specification that this
-// module implements: spec/DateKeys_Protocol_Specification_v0.9.md, tagged
-// spec-v0.9 in its repository. It is neither the version of the module (see
-// Version) nor the versions inside the objects: the capsule format, 1 or 2,
-// and the schema versions (spec §22, §70).
-const SpecVersion = "0.9"
+// module implements: spec/DateKeys_Protocol_Specification_v0.10.md, tagged
+// spec-v0.10 in its repository once it is closed. It is neither the version
+// of the module (see Version) nor the versions inside the objects: the
+// capsule format, 1 to 3, and the schema versions (spec §22, §70).
+const SpecVersion = "0.10"
 
 // modulePath is the path of this module: the import path of its root
 // package, whatever the module is called.