diff --git a/data/ext/pending/issue-4666-examples.txt b/data/ext/pending/issue-4666-examples.txt
new file mode 100644
index 000000000..3f18e4fde
--- /dev/null
+++ b/data/ext/pending/issue-4666-examples.txt
@@ -0,0 +1,50 @@
+TYPES: #eg-4666 Diet
+
+PRE-MARKUP:
+
+Basic JSON-LD example.
+
+MICRODATA:
+
+N/A
+
+RDFA:
+
+N/A
+
+JSON:
+
+<script type="application/ld+json">
+{
+  "@context": "https://schema.org",
+  "@type": "Recipe",
+  "name": "Avocado panzanella",
+  "image": "https://wwww.examplemenus.com/avopan.jpg",
+  "description": "A simple recipe for a quick and easy meal with avocado and sourdough (suitable for a low FODMAP diet).",
+  "suitableForDiet": [
+    {
+      "@type": "Diet",
+      "name": "Low FODMAP",
+      "description": "Low fermentable oligosaccharide, disaccharide, monosaccharide and polyol (FODMAP) diet.",
+      "sameAs": [
+        "https://en.wikipedia.org/wiki/Low-FODMAP_diet",
+        "http://snomed.info/sct/1255144000"
+      ],
+      "code": {
+        "@type": "MedicalCode",
+        "codeValue": "1255144000",
+        "codingSystem": "SNOMED-CT"
+      }
+    },
+    {
+      "@type": "Diet",
+      "name": "Mediterranean",
+      "description": "Diet based on the traditional eating habits of people in countries bordering the Mediterranean Sea.",
+      "sameAs": [
+        "https://en.wikipedia.org/wiki/Mediterranean_diet",
+        "https://www.ncbi.nlm.nih.gov/books/NBK557733/"
+      ]
+    }
+  ]
+}
+</script>
diff --git a/data/schema.ttl b/data/schema.ttl
index 43b831254..3b592c057 100644
--- a/data/schema.ttl
+++ b/data/schema.ttl
@@ -3567,6 +3567,10 @@ See also the <a href="/docs/hotels.html">dedicated document on the use of schema
     rdfs:comment "CassetteFormat." ;
     :contributor <https://schema.org/docs/collab/MBZ> .
 
+:CoeliacDiet a :RestrictedDiet ;
+    rdfs:label "CoeliacDiet" ;
+    rdfs:comment "A diet appropriate for people with coeliac (or celiac) disease. See also [gs1:DietTypeCode-COELIAC](https://ref.gs1.org/voc/DietTypeCode-COELIAC)" .
+
 :CoOp a :GamePlayMode ;
     rdfs:label "CoOp" ;
     rdfs:comment "Play mode: CoOp. Co-operative games, where you play on the same team with friends." .
@@ -3607,6 +3611,10 @@ See also the <a href="/docs/hotels.html">dedicated document on the use of schema
     rdfs:label "DiabeticDiet" ;
     rdfs:comment "A diet appropriate for people with diabetes." .
 
+:DieteticDiet a :RestrictedDiet ;
+    rdfs:label "DieteticDiet" ;
+    rdfs:comment "A diet for people on a restrictive diet. See also [gs1:DietTypeCode-DIETETIC](https://ref.gs1.org/voc/DietTypeCode-DIETETIC)" .
+
 :DigitalAudioTapeFormat a :MusicReleaseFormatType ;
     rdfs:label "DigitalAudioTapeFormat" ;
     rdfs:comment "DigitalAudioTapeFormat." ;
@@ -3679,7 +3687,7 @@ See also the <a href="/docs/hotels.html">dedicated document on the use of schema
 
 :GlutenFreeDiet a :RestrictedDiet ;
     rdfs:label "GlutenFreeDiet" ;
-    rdfs:comment "A diet exclusive of gluten." .
+    rdfs:comment "A diet exclusive of gluten. See also [gs1:DietTypeCode-FREE\\_FROM\\_GLUTEN](https://ref.gs1.org/voc/DietTypeCode-FREE_FROM_GLUTEN)" .
 
 :GroupBoardingPolicy a :BoardingPolicyType ;
     rdfs:label "GroupBoardingPolicy" ;
@@ -3687,7 +3695,7 @@ See also the <a href="/docs/hotels.html">dedicated document on the use of schema
 
 :HalalDiet a :RestrictedDiet ;
     rdfs:label "HalalDiet" ;
-    rdfs:comment "A diet conforming to Islamic dietary practices." .
+    rdfs:comment "A diet conforming to Islamic dietary practices. See also [gs1:DietTypeCode-HALAL](https://ref.gs1.org/voc/DietTypeCode-HALAL)" .
 
 :Hardcover a :BookFormatType ;
     rdfs:label "Hardcover" ;
@@ -3699,7 +3707,7 @@ See also the <a href="/docs/hotels.html">dedicated document on the use of schema
 
 :HinduDiet a :RestrictedDiet ;
     rdfs:label "HinduDiet" ;
-    rdfs:comment "A diet conforming to Hindu dietary practices, in particular, beef-free." .
+    rdfs:comment "A diet conforming to Hindu dietary practices." .
 
 :InStock a :ItemAvailability ;
     rdfs:label "InStock" ;
@@ -3723,7 +3731,7 @@ See also the <a href="/docs/hotels.html">dedicated document on the use of schema
 
 :KosherDiet a :RestrictedDiet ;
     rdfs:label "KosherDiet" ;
-    rdfs:comment "A diet conforming to Jewish dietary practices." .
+    rdfs:comment "A diet conforming to Jewish dietary practices. See also [gs1:DietTypeCode-KOSHER](https://ref.gs1.org/voc/DietTypeCode-KOSHER)" .
 
 :LaserDiscFormat a :MusicReleaseFormatType ;
     rdfs:label "LaserDiscFormat" ;
@@ -3846,6 +3854,10 @@ See also the <a href="/docs/hotels.html">dedicated document on the use of schema
     rdfs:label "OrderReturned" ;
     rdfs:comment "OrderStatus representing that an order has been returned." .
 
+:OrganicDiet a :RestrictedDiet ;
+    rdfs:label "OrganicDiet" ;
+    rdfs:comment "A diet without use of chemically formulated fertilisers, growth stimulants, antibiotics or pesticides (only with the use of feed or fertiliser of plant or animal origin). See also [gs1:DietTypeCode-ORGANIC](https://ref.gs1.org/voc/DietTypeCode-ORGANIC)" .
+
 :OutOfStock a :ItemAvailability ;
     rdfs:label "OutOfStock" ;
     rdfs:comment "Indicates that the item is out of stock." .
@@ -4026,11 +4038,11 @@ See also the <a href="/docs/hotels.html">dedicated document on the use of schema
 
 :VeganDiet a :RestrictedDiet ;
     rdfs:label "VeganDiet" ;
-    rdfs:comment "A diet exclusive of all animal products." .
+    rdfs:comment "A diet exclusive of all animal products. See also [gs1:DietTypeCode-VEGAN](https://ref.gs1.org/voc/DietTypeCode-VEGAN)." .
 
 :VegetarianDiet a :RestrictedDiet ;
     rdfs:label "VegetarianDiet" ;
-    rdfs:comment "A diet exclusive of animal meat." .
+    rdfs:comment "A diet exclusive of animal meat. See also [gs1:DietTypeCode-VEGETARIAN](https://ref.gs1.org/voc/DietTypeCode-VEGETARIAN)." .
 
 :VenueMap a :MapCategoryType ;
     rdfs:label "VenueMap" ;
@@ -4046,6 +4058,14 @@ See also the <a href="/docs/hotels.html">dedicated document on the use of schema
     rdfs:comment "The day of the week between Tuesday and Thursday." ;
     :sameAs <http://www.wikidata.org/entity/Q128> .
 
+:WithoutBeefDiet a :RestrictedDiet ;
+    rdfs:label "WithoutBeefDiet" ;
+    rdfs:comment "A diet without beef or beef-products. See also [gs1:DietTypeCode-WITHOUT\\_BEEF](https://ref.gs1.org/voc/DietTypeCode-WITHOUT_BEEF)." .
+
+:WithoutPorkDiet a :RestrictedDiet ;
+    rdfs:label "WithoutPorkDiet" ;
+    rdfs:comment "A diet without pork or pork-products. See also [gs1:DietTypeCode-WITHOUT\\_PORK](https://ref.gs1.org/voc/DietTypeCode-WITHOUT_PORK)." .
+
 :WritePermission a :DigitalDocumentPermissionType ;
     rdfs:label "WritePermission" ;
     rdfs:comment "Permission to write or edit the document." .