diff --git a/pkg/apis/resource/validation/validation.go b/pkg/apis/resource/validation/validation.go
index 3d411db46a3..2d5529c9532 100644
--- a/pkg/apis/resource/validation/validation.go
+++ b/pkg/apis/resource/validation/validation.go
@@ -33,6 +33,7 @@ import (
 	"k8s.io/apimachinery/pkg/api/operation"
 	apiresource "k8s.io/apimachinery/pkg/api/resource"
 	"k8s.io/apimachinery/pkg/api/validate"
+	"k8s.io/apimachinery/pkg/api/validate/content"
 	apimachineryvalidation "k8s.io/apimachinery/pkg/api/validation"
 	metav1validation "k8s.io/apimachinery/pkg/apis/meta/v1/validation"
 	"k8s.io/apimachinery/pkg/runtime"
@@ -1087,11 +1088,6 @@ func validateDeviceCounter(counter resource.Counter, fldPath *field.Path) field.
 
 func validateQualifiedName(name resource.QualifiedName, fldPath *field.Path) field.ErrorList {
 	var allErrs field.ErrorList
-	if name == "" {
-		allErrs = append(allErrs, field.Required(fldPath, "name required"))
-		return allErrs
-	}
-
 	parts := strings.Split(string(name), "/")
 	switch len(parts) {
 	case 1:
@@ -1125,15 +1121,11 @@ func validateQualifiedName(name resource.QualifiedName, fldPath *field.Path) fie
 
 func validateFullyQualifiedName(name resource.FullyQualifiedName, fldPath *field.Path) field.ErrorList {
 	var allErrs field.ErrorList
-	if name == "" {
-		allErrs = append(allErrs, field.Required(fldPath, "name required"))
-		return allErrs
-	}
 	allErrs = append(allErrs, validateQualifiedName(resource.QualifiedName(name), fldPath)...)
-	// validateQualifiedName checks that the name isn't empty and both parts are valid.
+	// validateQualifiedName checks that both parts are valid.
 	// What we need to enforce here is that there really is a domain.
-	if name != "" && !strings.Contains(string(name), "/") {
-		allErrs = append(allErrs, field.Invalid(fldPath, name, "must include a domain"))
+	if !strings.Contains(string(name), "/") {
+		allErrs = append(allErrs, field.Invalid(fldPath, name, "a fully qualified name must be a domain and a name separated by a slash"))
 	}
 	return allErrs.WithOrigin("format=k8s-resource-fully-qualified-name")
 }
@@ -1143,7 +1135,7 @@ func validateCIdentifier(id string, fldPath *field.Path) field.ErrorList {
 	if len(id) > resource.DeviceMaxIDLength {
 		allErrs = append(allErrs, field.TooLong(fldPath, "" /*unused*/, resource.DeviceMaxIDLength))
 	}
-	for _, msg := range validation.IsCIdentifier(id) {
+	for _, msg := range content.IsCIdentifier(id) {
 		allErrs = append(allErrs, field.Invalid(fldPath, id, msg))
 	}
 	return allErrs
diff --git a/pkg/apis/resource/validation/validation_resourceclaim_test.go b/pkg/apis/resource/validation/validation_resourceclaim_test.go
index 93c2d3d203c..598cfd6f2b0 100644
--- a/pkg/apis/resource/validation/validation_resourceclaim_test.go
+++ b/pkg/apis/resource/validation/validation_resourceclaim_test.go
@@ -263,8 +263,9 @@ func TestValidateClaim(t *testing.T) {
 				field.Invalid(field.NewPath("spec", "devices", "constraints").Index(0).Child("requests").Index(1), badName, "a lowercase RFC 1123 label must consist of lower case alphanumeric characters or '-', and must start and end with an alphanumeric character (e.g. 'my-name',  or '123-abc', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?')"),
 				field.Invalid(field.NewPath("spec", "devices", "constraints").Index(0).Child("requests").Index(1), badName, "must be the name of a request in the claim or the name of a request and a subrequest separated by '/'"),
 				field.Invalid(field.NewPath("spec", "devices", "constraints").Index(0).Child("matchAttribute"), "missing-domain", "a valid C identifier must start with alphabetic character or '_', followed by a string of alphanumeric characters or '_' (e.g. 'my_name',  or 'MY_NAME',  or 'MyName', regex used for validation is '[A-Za-z_][A-Za-z0-9_]*')").MarkCoveredByDeclarative(),
-				field.Invalid(field.NewPath("spec", "devices", "constraints").Index(0).Child("matchAttribute"), resource.FullyQualifiedName("missing-domain"), "must include a domain").MarkCoveredByDeclarative(),
-				field.Required(field.NewPath("spec", "devices", "constraints").Index(1).Child("matchAttribute"), "name required").MarkCoveredByDeclarative(),
+				field.Invalid(field.NewPath("spec", "devices", "constraints").Index(0).Child("matchAttribute"), resource.FullyQualifiedName("missing-domain"), "a fully qualified name must be a domain and a name separated by a slash").MarkCoveredByDeclarative(),
+				field.Invalid(field.NewPath("spec", "devices", "constraints").Index(1).Child("matchAttribute"), "", "a valid C identifier must start with alphabetic character or '_', followed by a string of alphanumeric characters or '_' (e.g. 'my_name',  or 'MY_NAME',  or 'MyName', regex used for validation is '[A-Za-z_][A-Za-z0-9_]*')").MarkCoveredByDeclarative(),
+				field.Invalid(field.NewPath("spec", "devices", "constraints").Index(1).Child("matchAttribute"), resource.FullyQualifiedName(""), "a fully qualified name must be a domain and a name separated by a slash").MarkCoveredByDeclarative(),
 				field.Required(field.NewPath("spec", "devices", "constraints").Index(2).Child("matchAttribute"), ""),
 				field.TooMany(field.NewPath("spec", "devices", "constraints"), resource.DeviceConstraintsMaxSize+1, resource.DeviceConstraintsMaxSize).MarkCoveredByDeclarative(),
 				field.Invalid(field.NewPath("spec", "devices", "config").Index(0).Child("requests").Index(1), badName, "a lowercase RFC 1123 label must consist of lower case alphanumeric characters or '-', and must start and end with an alphanumeric character (e.g. 'my-name',  or '123-abc', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?')"),
@@ -322,8 +323,9 @@ func TestValidateClaim(t *testing.T) {
 		"invalid-distinct-constraint": {
 			wantFailures: field.ErrorList{
 				field.Invalid(field.NewPath("spec", "devices", "constraints").Index(0).Child("distinctAttribute"), "missing-domain", "a valid C identifier must start with alphabetic character or '_', followed by a string of alphanumeric characters or '_' (e.g. 'my_name',  or 'MY_NAME',  or 'MyName', regex used for validation is '[A-Za-z_][A-Za-z0-9_]*')"),
-				field.Invalid(field.NewPath("spec", "devices", "constraints").Index(0).Child("distinctAttribute"), resource.FullyQualifiedName("missing-domain"), "must include a domain"),
-				field.Required(field.NewPath("spec", "devices", "constraints").Index(1).Child("distinctAttribute"), "name required"),
+				field.Invalid(field.NewPath("spec", "devices", "constraints").Index(0).Child("distinctAttribute"), resource.FullyQualifiedName("missing-domain"), "a fully qualified name must be a domain and a name separated by a slash"),
+				field.Invalid(field.NewPath("spec", "devices", "constraints").Index(1).Child("distinctAttribute"), "", "a valid C identifier must start with alphabetic character or '_', followed by a string of alphanumeric characters or '_' (e.g. 'my_name',  or 'MY_NAME',  or 'MyName', regex used for validation is '[A-Za-z_][A-Za-z0-9_]*')"),
+				field.Invalid(field.NewPath("spec", "devices", "constraints").Index(1).Child("distinctAttribute"), resource.FullyQualifiedName(""), "a fully qualified name must be a domain and a name separated by a slash"),
 				field.Required(field.NewPath("spec", "devices", "constraints").Index(2), `exactly one of "matchAttribute" or "distinctAttribute" is required, but multiple fields are set`)},
 			claim: func() *resource.ResourceClaim {
 				claim := testClaim(goodName, goodNS, validClaimSpec)
@@ -375,8 +377,9 @@ func TestValidateClaim(t *testing.T) {
 				field.Invalid(field.NewPath("spec", "devices", "constraints").Index(0).Child("requests").Index(1), badName, "a lowercase RFC 1123 label must consist of lower case alphanumeric characters or '-', and must start and end with an alphanumeric character (e.g. 'my-name',  or '123-abc', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?')"),
 				field.Invalid(field.NewPath("spec", "devices", "constraints").Index(0).Child("requests").Index(1), badName, "must be the name of a request in the claim or the name of a request and a subrequest separated by '/'"),
 				field.Invalid(field.NewPath("spec", "devices", "constraints").Index(0).Child("matchAttribute"), "missing-domain", "a valid C identifier must start with alphabetic character or '_', followed by a string of alphanumeric characters or '_' (e.g. 'my_name',  or 'MY_NAME',  or 'MyName', regex used for validation is '[A-Za-z_][A-Za-z0-9_]*')").MarkCoveredByDeclarative(),
-				field.Invalid(field.NewPath("spec", "devices", "constraints").Index(0).Child("matchAttribute"), resource.FullyQualifiedName("missing-domain"), "must include a domain").MarkCoveredByDeclarative(),
-				field.Required(field.NewPath("spec", "devices", "constraints").Index(1).Child("matchAttribute"), "name required").MarkCoveredByDeclarative(),
+				field.Invalid(field.NewPath("spec", "devices", "constraints").Index(0).Child("matchAttribute"), resource.FullyQualifiedName("missing-domain"), "a fully qualified name must be a domain and a name separated by a slash").MarkCoveredByDeclarative(),
+				field.Invalid(field.NewPath("spec", "devices", "constraints").Index(1).Child("matchAttribute"), "", "a valid C identifier must start with alphabetic character or '_', followed by a string of alphanumeric characters or '_' (e.g. 'my_name',  or 'MY_NAME',  or 'MyName', regex used for validation is '[A-Za-z_][A-Za-z0-9_]*')").MarkCoveredByDeclarative(),
+				field.Invalid(field.NewPath("spec", "devices", "constraints").Index(1).Child("matchAttribute"), resource.FullyQualifiedName(""), "a fully qualified name must be a domain and a name separated by a slash").MarkCoveredByDeclarative(),
 				field.Required(field.NewPath("spec", "devices", "constraints").Index(2).Child("matchAttribute"), ""),
 				field.Invalid(field.NewPath("spec", "devices", "config").Index(0).Child("requests").Index(1), badName, "a lowercase RFC 1123 label must consist of lower case alphanumeric characters or '-', and must start and end with an alphanumeric character (e.g. 'my-name',  or '123-abc', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?')"),
 				field.Invalid(field.NewPath("spec", "devices", "config").Index(0).Child("requests").Index(1), badName, "must be the name of a request in the claim or the name of a request and a subrequest separated by '/'"),
diff --git a/pkg/registry/resource/resourceclaim/declarative_validation_test.go b/pkg/registry/resource/resourceclaim/declarative_validation_test.go
index 6a53294e70c..ce39ea5d968 100644
--- a/pkg/registry/resource/resourceclaim/declarative_validation_test.go
+++ b/pkg/registry/resource/resourceclaim/declarative_validation_test.go
@@ -406,7 +406,7 @@ func testDeclarativeValidate(t *testing.T, apiVersion string) {
 				tweakMatchAttribute("nodomain"),
 			),
 			expectedErrs: field.ErrorList{
-				field.Invalid(field.NewPath("spec", "devices", "constraints").Index(0).Child("matchAttribute"), "nodomain", "must include a domain").WithOrigin("format=k8s-resource-fully-qualified-name"),
+				field.Invalid(field.NewPath("spec", "devices", "constraints").Index(0).Child("matchAttribute"), "nodomain", "a fully qualified name must be a domain and a name separated by a slash").WithOrigin("format=k8s-resource-fully-qualified-name"),
 			},
 		},
 		"match attribute empty": {
@@ -414,7 +414,7 @@ func testDeclarativeValidate(t *testing.T, apiVersion string) {
 				tweakMatchAttribute(""),
 			),
 			expectedErrs: field.ErrorList{
-				field.Required(field.NewPath("spec", "devices", "constraints").Index(0).Child("matchAttribute"), "name required"),
+				field.Invalid(field.NewPath("spec", "devices", "constraints").Index(0).Child("matchAttribute"), "", "").WithOrigin("format=k8s-resource-fully-qualified-name"),
 			},
 		},
 		"match attribute with empty domain": {
diff --git a/staging/src/k8s.io/api/resource/v1/types.go b/staging/src/k8s.io/api/resource/v1/types.go
index 53d261c4344..f698be61969 100644
--- a/staging/src/k8s.io/api/resource/v1/types.go
+++ b/staging/src/k8s.io/api/resource/v1/types.go
@@ -568,6 +568,9 @@ const ResourceSliceMaxDeviceCountersPerSlice = 1024 // 64 * 16
 type QualifiedName string
 
 // FullyQualifiedName is a QualifiedName where the domain is set.
+// Format validation cannot be added to this type because one of its usages,
+// DistinctAttribute, is validated conditionally. This conditional validation
+// cannot be expressed declaratively.
 type FullyQualifiedName string
 
 // DeviceMaxDomainLength is the maximum length of the domain prefix in a fully-qualified name.
diff --git a/staging/src/k8s.io/api/resource/v1beta1/types.go b/staging/src/k8s.io/api/resource/v1beta1/types.go
index a1ea50f354d..e63de0d1bcc 100644
--- a/staging/src/k8s.io/api/resource/v1beta1/types.go
+++ b/staging/src/k8s.io/api/resource/v1beta1/types.go
@@ -572,6 +572,9 @@ const ResourceSliceMaxDeviceCountersPerSlice = 1024 // 64 * 16
 type QualifiedName string
 
 // FullyQualifiedName is a QualifiedName where the domain is set.
+// Format validation cannot be added to this type because one of its usages,
+// DistinctAttribute, is validated conditionally. This conditional validation
+// cannot be expressed declaratively.
 type FullyQualifiedName string
 
 // DeviceMaxDomainLength is the maximum length of the domain prefix in a fully-qualified name.
diff --git a/staging/src/k8s.io/api/resource/v1beta2/types.go b/staging/src/k8s.io/api/resource/v1beta2/types.go
index 2bb5a70d22d..c3e06f3edb5 100644
--- a/staging/src/k8s.io/api/resource/v1beta2/types.go
+++ b/staging/src/k8s.io/api/resource/v1beta2/types.go
@@ -568,6 +568,9 @@ const ResourceSliceMaxDeviceCountersPerSlice = 1024 // 64 * 16
 type QualifiedName string
 
 // FullyQualifiedName is a QualifiedName where the domain is set.
+// Format validation cannot be added to this type because one of its usages,
+// DistinctAttribute, is validated conditionally. This conditional validation
+// cannot be expressed declaratively.
 type FullyQualifiedName string
 
 // DeviceMaxDomainLength is the maximum length of the domain prefix in a fully-qualified name.
diff --git a/staging/src/k8s.io/apimachinery/pkg/api/validate/content/identifier.go b/staging/src/k8s.io/apimachinery/pkg/api/validate/content/identifier.go
index eb1b25d5ca9..3913ec99163 100644
--- a/staging/src/k8s.io/apimachinery/pkg/api/validate/content/identifier.go
+++ b/staging/src/k8s.io/apimachinery/pkg/api/validate/content/identifier.go
@@ -1,3 +1,19 @@
+/*
+Copyright 2025 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
 package content
 
 import (
diff --git a/staging/src/k8s.io/apimachinery/pkg/api/validate/content/identifier_test.go b/staging/src/k8s.io/apimachinery/pkg/api/validate/content/identifier_test.go
index 036137c232c..e5c1bf84ab2 100644
--- a/staging/src/k8s.io/apimachinery/pkg/api/validate/content/identifier_test.go
+++ b/staging/src/k8s.io/apimachinery/pkg/api/validate/content/identifier_test.go
@@ -1,3 +1,19 @@
+/*
+Copyright 2025 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
 package content
 
 import (
diff --git a/staging/src/k8s.io/apimachinery/pkg/api/validate/strfmt.go b/staging/src/k8s.io/apimachinery/pkg/api/validate/strfmt.go
index 9da8e3ad95a..9a21473055f 100644
--- a/staging/src/k8s.io/apimachinery/pkg/api/validate/strfmt.go
+++ b/staging/src/k8s.io/apimachinery/pkg/api/validate/strfmt.go
@@ -23,7 +23,6 @@ import (
 
 	"k8s.io/apimachinery/pkg/api/operation"
 	"k8s.io/apimachinery/pkg/api/validate/content"
-	"k8s.io/apimachinery/pkg/util/validation"
 	"k8s.io/apimachinery/pkg/util/validation/field"
 )
 
@@ -32,7 +31,7 @@ const (
 	defaultResourceRequestsPrefix = "requests."
 	// Default namespace prefix.
 	resourceDefaultNamespacePrefix = "kubernetes.io/"
-	cDeviceMaxLength               = 32
+	resourceDeviceMaxLength        = 32
 )
 
 // ShortName verifies that the specified value is a valid "short name"
@@ -234,15 +233,13 @@ func resourcesQualifiedName[T ~string](ctx context.Context, op operation.Operati
 	}
 	var allErrs field.ErrorList
 	s := string(*value)
-	if len(s) == 0 {
-		allErrs = append(allErrs, field.Required(fldPath, "name required"))
-		return allErrs
-	}
-
 	parts := strings.Split(s, "/")
+	// TODO: This validation and the corresponding handwritten validation validateQualifiedName in
+	// pkg/apis/resource/validation/validation.go are not validating whether there are more than 1
+	// slash. This should be fixed in both places.
 	switch len(parts) {
 	case 1:
-		allErrs = append(allErrs, validateCIdentifier(parts[0], fldPath)...)
+		allErrs = append(allErrs, validateCIdentifier(parts[0], resourceDeviceMaxLength, fldPath)...)
 	case 2:
 		if len(parts[0]) == 0 {
 			allErrs = append(allErrs, field.Invalid(fldPath, "", "prefix must not be empty"))
@@ -255,11 +252,8 @@ func resourcesQualifiedName[T ~string](ctx context.Context, op operation.Operati
 		if len(parts[1]) == 0 {
 			allErrs = append(allErrs, field.Invalid(fldPath, "", "name must not be empty"))
 		} else {
-			allErrs = append(allErrs, validateCIdentifier(parts[1], fldPath)...)
+			allErrs = append(allErrs, validateCIdentifier(parts[1], resourceDeviceMaxLength, fldPath)...)
 		}
-		// TODO: This validation and the corresponding handwritten validation validateQualifiedName in
-		// pkg/apis/resource/validation/validation.go are not validating whether there are more than 1
-		// slash. This should be fixed in both places.
 	}
 	return allErrs
 }
@@ -276,25 +270,20 @@ func ResourceFullyQualifiedName[T ~string](ctx context.Context, op operation.Ope
 		return nil
 	}
 	var allErrs field.ErrorList
-	if len(*value) == 0 {
-		allErrs = append(allErrs, field.Required(fldPath, "name can't be empty"))
-		return allErrs
-	}
-
 	s := string(*value)
-	allErrs = append(allErrs, resourcesQualifiedName(ctx, op, fldPath, value, nil)...)
+	allErrs = append(allErrs, resourcesQualifiedName(ctx, op, fldPath, &s, nil)...)
 	if !strings.Contains(s, "/") {
-		allErrs = append(allErrs, field.Invalid(fldPath, s, "a fully qualified name must be a prefix and a name separated by a slash"))
+		allErrs = append(allErrs, field.Invalid(fldPath, s, "a fully qualified name must be a domain and a name separated by a slash"))
 	}
 	return allErrs.WithOrigin("format=k8s-resource-fully-qualified-name")
 }
 
-func validateCIdentifier(id string, fldPath *field.Path) field.ErrorList {
+func validateCIdentifier(id string, length int, fldPath *field.Path) field.ErrorList {
 	var allErrs field.ErrorList
-	if len(id) > cDeviceMaxLength {
-		allErrs = append(allErrs, field.TooLong(fldPath, id, cDeviceMaxLength))
+	if len(id) > length {
+		allErrs = append(allErrs, field.TooLong(fldPath, id, length))
 	}
-	for _, msg := range validation.IsCIdentifier(id) {
+	for _, msg := range content.IsCIdentifier(id) {
 		allErrs = append(allErrs, field.Invalid(fldPath, id, msg))
 	}
 	return allErrs
diff --git a/staging/src/k8s.io/apimachinery/pkg/api/validate/strfmt_test.go b/staging/src/k8s.io/apimachinery/pkg/api/validate/strfmt_test.go
index a6d81514b73..a3c20926530 100644
--- a/staging/src/k8s.io/apimachinery/pkg/api/validate/strfmt_test.go
+++ b/staging/src/k8s.io/apimachinery/pkg/api/validate/strfmt_test.go
@@ -680,25 +680,26 @@ func TestResourceFullyQualifiedName(t *testing.T) {
 		name:  "invalid name with dots",
 		input: "prefix.com/name.with.dots",
 		wantErrs: field.ErrorList{
-			field.Invalid(fldPath, "name.with.dots", "a valid C identifier must start with alphabetic character or '_', followed by a string of alphanumeric characters or '_' (e.g. 'my_name',  or 'MY_NAME',  or 'MyName', regex used for validation is '[A-Za-z_][A-Za-z0-9_]*')").WithOrigin("format=k8s-resource-fully-qualified-name"),
+			field.Invalid(fldPath, "name.with.dots", "a valid C identifier must start with alphabetic character").WithOrigin("format=k8s-resource-fully-qualified-name"),
 		},
 	}, {
 		name:  "invalid name with dashes",
 		input: "prefix.com/name-with-dashes",
 		wantErrs: field.ErrorList{
-			field.Invalid(fldPath, "name-with-dashes", "a valid C identifier must start with alphabetic character or '_', followed by a string of alphanumeric characters or '_' (e.g. 'my_name',  or 'MY_NAME',  or 'MyName', regex used for validation is '[A-Za-z_][A-Za-z0-9_]*')").WithOrigin("format=k8s-resource-fully-qualified-name"),
+			field.Invalid(fldPath, "name-with-dashes", "a valid C identifier must start with alphabetic character").WithOrigin("format=k8s-resource-fully-qualified-name"),
 		},
 	}, {
 		name:  "invalid: no prefix",
 		input: "name",
 		wantErrs: field.ErrorList{
-			field.Invalid(fldPath, "name", "a fully qualified name must be a prefix and a name separated by a slash").WithOrigin("format=k8s-resource-fully-qualified-name"),
+			field.Invalid(fldPath, "name", "a fully qualified name must be a domain and a name separated by a slash").WithOrigin("format=k8s-resource-fully-qualified-name"),
 		},
 	}, {
 		name:  "invalid: empty",
 		input: "",
 		wantErrs: field.ErrorList{
-			field.Required(fldPath, "name can't be empty"),
+			field.Invalid(fldPath, "", "a fully qualified name must be a domain and a name separated by a slash").WithOrigin("format=k8s-resource-fully-qualified-name"),
+			field.Invalid(fldPath, "", "a valid C identifier must start with alphabetic character").WithOrigin("format=k8s-resource-fully-qualified-name"),
 		},
 	}, {
 		name:  "invalid: prefix too long",
@@ -717,7 +718,7 @@ func TestResourceFullyQualifiedName(t *testing.T) {
 		name:  "invalid: prefix is not a valid DNS subdomain",
 		input: "Prefix.com/name",
 		wantErrs: field.ErrorList{
-			field.Invalid(fldPath, "Prefix.com", "prefix: a lowercase RFC 1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character").WithOrigin("format=k8s-resource-fully-qualified-name"),
+			field.Invalid(fldPath, "Prefix.com", "prefix: a lowercase RFC 1123 subdomain must consist of lower case alphanumeric characters").WithOrigin("format=k8s-resource-fully-qualified-name"),
 		},
 	}, {
 		name:     "invalid: name is not a valid RFC 1123 label",
diff --git a/staging/src/k8s.io/apimachinery/pkg/util/validation/validation.go b/staging/src/k8s.io/apimachinery/pkg/util/validation/validation.go
index 8e76c313757..95f78e92fa7 100644
--- a/staging/src/k8s.io/apimachinery/pkg/util/validation/validation.go
+++ b/staging/src/k8s.io/apimachinery/pkg/util/validation/validation.go
@@ -237,19 +237,10 @@ func IsWildcardDNS1123Subdomain(value string) []string {
 	return errs
 }
 
-const cIdentifierFmt string = "[A-Za-z_][A-Za-z0-9_]*"
-const identifierErrMsg string = "a valid C identifier must start with alphabetic character or '_', followed by a string of alphanumeric characters or '_'"
-
-var cIdentifierRegexp = regexp.MustCompile("^" + cIdentifierFmt + "$")
-
 // IsCIdentifier tests for a string that conforms the definition of an identifier
 // in C. This checks the format, but not the length.
-func IsCIdentifier(value string) []string {
-	if !cIdentifierRegexp.MatchString(value) {
-		return []string{RegexError(identifierErrMsg, cIdentifierFmt, "my_name", "MY_NAME", "MyName")}
-	}
-	return nil
-}
+// Deprecated: Use k8s.io/apimachinery/pkg/api/validate/content.IsCIdentifier instead.
+var IsCIdentifier = content.IsCIdentifier
 
 // IsValidPortNum tests that the argument is a valid, non-zero port number.
 func IsValidPortNum(port int) []string {
diff --git a/staging/src/k8s.io/apimachinery/pkg/util/validation/validation_test.go b/staging/src/k8s.io/apimachinery/pkg/util/validation/validation_test.go
index acfe2cb7687..bd01941228d 100644
--- a/staging/src/k8s.io/apimachinery/pkg/util/validation/validation_test.go
+++ b/staging/src/k8s.io/apimachinery/pkg/util/validation/validation_test.go
@@ -116,31 +116,6 @@ func TestIsDNS1035Label(t *testing.T) {
 	}
 }
 
-func TestIsCIdentifier(t *testing.T) {
-	goodValues := []string{
-		"a", "ab", "abc", "a1", "_a", "a_", "a_b", "a_1", "a__1__2__b", "__abc_123",
-		"A", "AB", "AbC", "A1", "_A", "A_", "A_B", "A_1", "A__1__2__B", "__123_ABC",
-	}
-	for _, val := range goodValues {
-		if msgs := IsCIdentifier(val); len(msgs) != 0 {
-			t.Errorf("expected true for '%s': %v", val, msgs)
-		}
-	}
-
-	badValues := []string{
-		"", "1", "123", "1a",
-		"-", "a-", "-a", "1-", "-1", "1_", "1_2",
-		".", "a.", ".a", "a.b", "1.", ".1", "1.2",
-		" ", "a ", " a", "a b", "1 ", " 1", "1 2",
-		"#a#",
-	}
-	for _, val := range badValues {
-		if msgs := IsCIdentifier(val); len(msgs) == 0 {
-			t.Errorf("expected false for '%s'", val)
-		}
-	}
-}
-
 func TestIsValidPortNum(t *testing.T) {
 	goodValues := []int{1, 2, 1000, 16384, 32768, 65535}
 	for _, val := range goodValues {
diff --git a/staging/src/k8s.io/code-generator/cmd/validation-gen/output_tests/tags/format/k8s-resource-fully-qualified-name/doc_test.go b/staging/src/k8s.io/code-generator/cmd/validation-gen/output_tests/tags/format/k8s-resource-fully-qualified-name/doc_test.go
index 67d1fb66c17..6d4768b74fa 100644
--- a/staging/src/k8s.io/code-generator/cmd/validation-gen/output_tests/tags/format/k8s-resource-fully-qualified-name/doc_test.go
+++ b/staging/src/k8s.io/code-generator/cmd/validation-gen/output_tests/tags/format/k8s-resource-fully-qualified-name/doc_test.go
@@ -38,9 +38,9 @@ func TestFullyQualifiedName(t *testing.T) {
 		FullyQualifiedNameTypedefField: "my-prefix/",
 	}
 	st.Value(invalidStruct).ExpectMatches(field.ErrorMatcher{}.ByType().ByOrigin().ByField(), field.ErrorList{
-		field.Invalid(field.NewPath("fullyQualifiedNameField"), "my_name", "").WithOrigin("format=k8s-resource-fully-qualified-name"),
-		field.Required(field.NewPath("fullyQualifiedNamePtrField"), ""),
-		field.Invalid(field.NewPath("fullyQualifiedNameTypedefField"), "my-prefix/", "").WithOrigin("format=k8s-resource-fully-qualified-name"),
+		field.Invalid(field.NewPath("fullyQualifiedNameField"), "my_name", "a fully qualified name must be a domain and a name separated by a slash").WithOrigin("format=k8s-resource-fully-qualified-name"),
+		field.Invalid(field.NewPath("fullyQualifiedNamePtrField"), "", "a valid C identifier must start with alphabetic character or '_', followed by a string of alphanumeric characters or '_'").WithOrigin("format=k8s-resource-fully-qualified-name"),
+		field.Invalid(field.NewPath("fullyQualifiedNameTypedefField"), "my-prefix/", "name must not be empty").WithOrigin("format=k8s-resource-fully-qualified-name"),
 	})
 	// Test validation ratcheting
 	st.Value(invalidStruct).OldValue(invalidStruct).ExpectValid()
diff --git a/staging/src/k8s.io/code-generator/cmd/validation-gen/validators/format.go b/staging/src/k8s.io/code-generator/cmd/validation-gen/validators/format.go
index d35294f0f2f..54322e05626 100644
--- a/staging/src/k8s.io/code-generator/cmd/validation-gen/validators/format.go
+++ b/staging/src/k8s.io/code-generator/cmd/validation-gen/validators/format.go
@@ -143,7 +143,7 @@ func (ftv formatTagValidator) Docs() TagDoc {
 			Docs:        "Deprecated: This field holds a case-insensitive Kubernetes \"long name\", aka a \"DNS subdomain\" value.",
 		}, {
 			Description: "k8s-resource-fully-qualified-name",
-			Docs:        "This field holds a Kubernetes resource \"fully qualified name\" value.",
+			Docs:        "This field holds a Kubernetes resource \"fully qualified name\" value. A fully qualified name must not be empty and must be composed of a prefix and a name, separated by a slash (e.g., \"prefix/name\"). The prefix must be a DNS subdomain, and the name part must be a C identifier with no more than 32 characters.",
 		}, {
 			Description: "k8s-resource-pool-name",
 			Docs:        "This field holds value with one or more Kubernetes \"long name\" parts separated by `/` and no longer than 253 characters.",