diff --git a/processor/processor.go b/processor/processor.go
index 6939e4d..bdcf5c7 100644
--- a/processor/processor.go
+++ b/processor/processor.go
@@ -505,6 +505,14 @@ func mkRegistry(customMarkers []config.Marker) (*markers.Registry, error) {
 		}
 	}
 
+	// Register k8s:* markers - sig apimachinery plans to unify CRD and native types on these.
+	if err := registry.Define("k8s:required", markers.DescribesField, struct{}{}); err != nil {
+		return nil, err
+	}
+	if err := registry.Define("k8s:optional", markers.DescribesField, struct{}{}); err != nil {
+		return nil, err
+	}
+
 	for _, marker := range customMarkers {
 		t := markers.DescribesField
 		switch marker.Target {
@@ -554,6 +562,17 @@ func parseMarkers(markers markers.MarkerValues) (string, []string) {
 			validation = append(validation, fmt.Sprintf("%s: %v", name, value))
 		}
 
+		// Handle standalone +required and +k8s:required marker
+		// This is equivalent to +kubebuilder:validation:Required
+		if name == "required" || name == "k8s:required" {
+			validation = append(validation, "Required: {}")
+		}
+		// Handle standalone +optional and +k8s:optional marker
+		// This is equivalent to +kubebuilder:validation:Optional
+		if name == "optional" || name == "k8s:optional" {
+			validation = append(validation, "Optional: {}")
+		}
+
 		if name == "kubebuilder:default" {
 			if value, ok := value.(crdmarkers.Default); ok {
 				defaultValue = fmt.Sprintf("%v", value.Value)
diff --git a/renderer/asciidoctor.go b/renderer/asciidoctor.go
index 6598266..695f2c2 100644
--- a/renderer/asciidoctor.go
+++ b/renderer/asciidoctor.go
@@ -151,7 +151,7 @@ func (adr *AsciidoctorRenderer) TemplateValue(key string) string {
 func (adr *AsciidoctorRenderer) RenderFieldDoc(text string) string {
 	// Escape the pipe character, which has special meaning for asciidoc as a way to format tables,
 	// so that including | in a comment does not result in wonky tables.
-	out := strings.ReplaceAll(text, "|", "\\|")
+	out := escapePipe(text)
 
 	// Trim any leading and trailing whitespace from each line.
 	lines := strings.Split(out, "\n")
@@ -169,6 +169,7 @@ func (adr *AsciidoctorRenderer) RenderFieldDoc(text string) string {
 
 func (adr *AsciidoctorRenderer) RenderValidation(text string) string {
 	renderedText := escapeFirstAsterixInEachPair(text)
+	renderedText = escapePipe(renderedText)
 	return escapeCurlyBraces(renderedText)
 }
 
@@ -190,9 +191,15 @@ func escapeFirstAsterixInEachPair(text string) string {
 	return text
 }
 
+// escapePipe ensures sufficient escapes are added to pipe characters, so they are not mistaken
+// for asciidoctor table formatting.
+func escapePipe(text string) string {
+	return strings.ReplaceAll(text, "|", "\\|")
+}
+
 // escapeCurlyBraces ensures sufficient escapes are added to curly braces, so they are not mistaken
 // for asciidoctor id attributes.
 func escapeCurlyBraces(text string) string {
 	// Per asciidoctor docs, only the leading curly brace needs to be escaped.
-	return strings.Replace(text, "{", "\\{", -1)
+	return strings.ReplaceAll(text, "{", "\\{")
 }
diff --git a/renderer/asciidoctor_test.go b/renderer/asciidoctor_test.go
index 124f659..2fb1e92 100644
--- a/renderer/asciidoctor_test.go
+++ b/renderer/asciidoctor_test.go
@@ -19,3 +19,8 @@ func Test_escapeCurlyBraces(t *testing.T) {
 	assert.Equal(t, "[a-fA-F0-9]\\{64}", escapeCurlyBraces("[a-fA-F0-9]{64}"))
 	assert.Equal(t, "[a-fA-F0-9]\\\\{64\\}", escapeCurlyBraces("[a-fA-F0-9]\\{64\\}"))
 }
+
+func Test_escapePipe(t *testing.T) {
+	assert.Equal(t, "[0-9]", escapePipe("[0-9]"))
+	assert.Equal(t, `[0-9]*\|\s`, escapePipe(`[0-9]*|\s`))
+}
diff --git a/test/api/v1/guestbook_types.go b/test/api/v1/guestbook_types.go
index 5dbdcb0..1dac6e1 100644
--- a/test/api/v1/guestbook_types.go
+++ b/test/api/v1/guestbook_types.go
@@ -124,6 +124,7 @@ type PositiveInt int
 // GuestbookEntry defines an entry in a guest book.
 type GuestbookEntry struct {
 	// Name of the guest (pipe | should be escaped)
+	// +kubebuilder:validation:Required
 	// +kubebuilder:validation:MaxLength=80
 	// +kubebuilder:validation:Pattern=`0*[a-z0-9]*[a-z]*[0-9]`
 	Name string `json:"name,omitempty"`
@@ -146,6 +147,19 @@ type GuestbookEntry struct {
 	Comment string `json:"comment,omitempty"`
 	// Rating provided by the guest
 	Rating Rating `json:"rating,omitempty"`
+
+	// Email is the email address of the guest (required field using +required marker)
+	// +required
+	Email string `json:"email"`
+	// Location is the location of the guest (required field using +k8s:required marker)
+	// +k8s:required
+	Location string `json:"location"`
+	// Phone is the phone number of the guest (optional field using +optional marker)
+	// +optional
+	Phone string `json:"phone"`
+	// Company is the company of the guest (optional field using +k8s:optional marker)
+	// +k8s:optional
+	Company string `json:"company"`
 }
 
 // GuestbookStatus defines the observed state of Guestbook.
diff --git a/test/expected.asciidoc b/test/expected.asciidoc
index a5a642e..dff065f 100644
--- a/test/expected.asciidoc
+++ b/test/expected.asciidoc
@@ -162,6 +162,7 @@ GuestbookEntry defines an entry in a guest book.
 | Field | Description | Default | Validation
 | *`name`* __string__ | Name of the guest (pipe \| should be escaped) + |  | MaxLength: 80 +
 Pattern: `0\*[a-z0-9]*[a-z]*[0-9]` +
+Required: \{} +
 
 | *`tags`* __string array__ | Tags of the entry. + |  | items:Pattern: `[a-z]*` +
 
@@ -174,11 +175,19 @@ Now let's test a list: +
 
 Another isolated comment. +
 
-Looks good? + |  | Pattern: `0\*[a-z0-9]*[a-z]\*[0-9]*|\s` +
+Looks good? + |  | Pattern: `0\*[a-z0-9]*[a-z]\*[0-9]*\|\s` +
 
 | *`rating`* __xref:{anchor_prefix}-github-com-elastic-crd-ref-docs-api-v1-rating[$$Rating$$]__ | Rating provided by the guest + |  | Maximum: 5 +
 Minimum: 1 +
 
+| *`email`* __string__ | Email is the email address of the guest (required field using +required marker) + |  | Required: \{} +
+
+| *`location`* __string__ | Location is the location of the guest (required field using +k8s:required marker) + |  | Required: \{} +
+
+| *`phone`* __string__ | Phone is the phone number of the guest (optional field using +optional marker) + |  | Optional: \{} +
+
+| *`company`* __string__ | Company is the company of the guest (optional field using +k8s:optional marker) + |  | Optional: \{} +
+
 |===
 
 
diff --git a/test/expected.md b/test/expected.md
index a3678da..538adf6 100644
--- a/test/expected.md
+++ b/test/expected.md
@@ -127,11 +127,15 @@ _Appears in:_
 
 | Field | Description | Default | Validation |
 | --- | --- | --- | --- |
-| `name` _string_ | Name of the guest (pipe \| should be escaped) |  | MaxLength: 80 <br />Pattern: `0*[a-z0-9]*[a-z]*[0-9]` <br /> |
+| `name` _string_ | Name of the guest (pipe \| should be escaped) |  | MaxLength: 80 <br />Pattern: `0*[a-z0-9]*[a-z]*[0-9]` <br />Required: \{\} <br /> |
 | `tags` _string array_ | Tags of the entry. |  | items:Pattern: `[a-z]*` <br /> |
 | `time` _[Time](https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.25/#time-v1-meta)_ | Time of entry |  |  |
 | `comment` _string_ | Comment by guest. This can be a multi-line comment.<br />Like this one.<br />Now let's test a list:<br />* a<br />* b<br />Another isolated comment.<br />Looks good? |  | Pattern: `0*[a-z0-9]*[a-z]*[0-9]*\|\s` <br /> |
 | `rating` _[Rating](#rating)_ | Rating provided by the guest |  | Maximum: 5 <br />Minimum: 1 <br /> |
+| `email` _string_ | Email is the email address of the guest (required field using +required marker) |  | Required: \{\} <br /> |
+| `location` _string_ | Location is the location of the guest (required field using +k8s:required marker) |  | Required: \{\} <br /> |
+| `phone` _string_ | Phone is the phone number of the guest (optional field using +optional marker) |  | Optional: \{\} <br /> |
+| `company` _string_ | Company is the company of the guest (optional field using +k8s:optional marker) |  | Optional: \{\} <br /> |
 
 
 #### GuestbookHeader
diff --git a/test/hide.md b/test/hide.md
index 1757e3b..d274f96 100644
--- a/test/hide.md
+++ b/test/hide.md
@@ -128,11 +128,15 @@ _Appears in:_
 
 | Field | Description | Default | Validation |
 | --- | --- | --- | --- |
-| `name` _string_ | Name of the guest (pipe \| should be escaped) |  | MaxLength: 80 <br />Pattern: `0*[a-z0-9]*[a-z]*[0-9]` <br /> |
+| `name` _string_ | Name of the guest (pipe \| should be escaped) |  | MaxLength: 80 <br />Pattern: `0*[a-z0-9]*[a-z]*[0-9]` <br />Required: \{\} <br /> |
 | `tags` _string array_ | Tags of the entry. |  | items:Pattern: `[a-z]*` <br /> |
 | `time` _[Time](https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.25/#time-v1-meta)_ | Time of entry |  |  |
 | `comment` _string_ | Comment by guest. This can be a multi-line comment.<br />Like this one.<br />Now let's test a list:<br />* a<br />* b<br />Another isolated comment.<br />Looks good? |  | Pattern: `0*[a-z0-9]*[a-z]*[0-9]*\|\s` <br /> |
 | `rating` _[Rating](#rating)_ | Rating provided by the guest |  | Maximum: 5 <br />Minimum: 1 <br /> |
+| `email` _string_ | Email is the email address of the guest (required field using +required marker) |  | Required: \{\} <br /> |
+| `location` _string_ | Location is the location of the guest (required field using +k8s:required marker) |  | Required: \{\} <br /> |
+| `phone` _string_ | Phone is the phone number of the guest (optional field using +optional marker) |  | Optional: \{\} <br /> |
+| `company` _string_ | Company is the company of the guest (optional field using +k8s:optional marker) |  | Optional: \{\} <br /> |
 
 
 #### GuestbookHeader