diff --git a/schema/sssom-docs/Mapping.md b/schema/sssom-docs/Mapping.md
index c4839aba..779ffc17 100644
--- a/schema/sssom-docs/Mapping.md
+++ b/schema/sssom-docs/Mapping.md
@@ -7,7 +7,7 @@ Represents an individual mapping between a pair of entities
 URI: [sssom:Mapping](http://w3id.org/sssom/Mapping)
 
 
-![img](http://yuml.me/diagram/nofunky;dir:TB/class/[Entity]<object_match_field%200..1-%20[Mapping&#124;subject_label:string%20%3F;subject_category:string%20%3F;predicate_label:string%20%3F;object_label:string%20%3F;object_category:string%20%3F;match_type:string%20%3F;creator_label:string%20%3F;license:string%20%3F;subject_source:string%20%3F;subject_source_version:string%20%3F;object_source:string%20%3F;object_source_version:string%20%3F;mapping_provider:string%20%3F;mapping_cardinality:string%20%3F;mapping_tool:string%20%3F;mapping_date:string%20%3F;confidence:double%20%3F;match_string:string%20%3F;subject_preprocessing:string%20%3F;object_preprocessing:string%20%3F;match_term_type:string%20%3F;semantic_similarity_score:double%20%3F;information_content_mica_score:double%20%3F;see_also:string%20%3F;other:string%20%3F;comment:string%20%3F],[Entity]<subject_match_field%200..1-%20[Mapping],[Entity]<creator_id%200..1-%20[Mapping],[Entity]<object_id%200..1-%20[Mapping],[Entity]<predicate_id%200..1-%20[Mapping],[Entity]<subject_id%200..1-%20[Mapping],[MappingSet]++-%20mappings%200..*>[Mapping],[MappingSet],[Entity])
+![img](http://yuml.me/diagram/nofunky;dir:TB/class/[Entity]<object_match_field%200..1-%20[Mapping&#124;subject_label:string%20%3F;subject_category:string%20%3F;predicate_label:string%20%3F;object_label:string%20%3F;object_category:string%20%3F;match_type:string%20%3F;creator_label:string%20%3F;license:string%20%3F;subject_source:string%20%3F;subject_source_version:string%20%3F;object_source:string%20%3F;object_source_version:string%20%3F;mapping_provider:string%20%3F;mapping_cardinality:mapping_cardinality_enum%20%3F;mapping_tool:string%20%3F;mapping_date:string%20%3F;confidence:double%20%3F;match_string:string%20%3F;subject_preprocessing:string%20%3F;object_preprocessing:string%20%3F;match_term_type:string%20%3F;semantic_similarity_score:double%20%3F;information_content_mica_score:double%20%3F;see_also:string%20%3F;other:string%20%3F;comment:string%20%3F],[Entity]<subject_match_field%200..1-%20[Mapping],[Entity]<creator_id%200..1-%20[Mapping],[Entity]<object_id%200..1-%20[Mapping],[Entity]<predicate_id%200..1-%20[Mapping],[Entity]<subject_id%200..1-%20[Mapping],[MappingSet]++-%20mappings%200..*>[Mapping],[MappingSet],[Entity])
 
 ## Referenced by class
 
@@ -38,7 +38,7 @@ URI: [sssom:Mapping](http://w3id.org/sssom/Mapping)
      * range: [String](types/String.md)
  * [mapping_cardinality](mapping_cardinality.md)  <sub>OPT</sub>
      * Description: A string indicating whether this mapping is from a 1:1 (the subject_id maps to a single object_id), 1:n (the subject maps to more than one object_id), n:1, 1:0, 0:1 or n:n group. Note that this is a convenience field that should be derivable from the mapping set.
-     * range: [String](types/String.md)
+     * range: 
  * [mapping_date](mapping_date.md)  <sub>OPT</sub>
      * Description: The date the mapping was computed
      * range: [String](types/String.md)
diff --git a/schema/sssom.context.jsonld b/schema/sssom.context.jsonld
index 6282c486..8fa7a22f 100644
--- a/schema/sssom.context.jsonld
+++ b/schema/sssom.context.jsonld
@@ -1,5 +1,5 @@
 {
-   "_comments": "Auto generated from sssom.yaml by jsonldcontextgen.py version: 0.1.1\n    Generation date: 2021-06-17 16:27\n    Schema: sssom\n    \n    id: http://w3id.org/sssom/schema/\n    description: Datamodel for Simple Standard for Sharing Ontology Mappings (SSSOM)\n    license: https://creativecommons.org/publicdomain/zero/1.0/\n    ",
+   "_comments": "Auto generated from sssom.yaml by jsonldcontextgen.py version: 0.1.1\n    Generation date: 2021-06-22 10:25\n    Schema: sssom\n    \n    id: http://w3id.org/sssom/schema/\n    description: Datamodel for Simple Standard for Sharing Ontology Mappings (SSSOM)\n    license: https://creativecommons.org/publicdomain/zero/1.0/\n    ",
    "@context": {
       "dc": "http://purl.org/dc/terms/",
       "dcterms": "http://purl.org/dc/terms/",
@@ -8,6 +8,7 @@
       "owl": "http://www.w3.org/2002/07/owl#",
       "rdf": "http://www.w3.org/1999/02/22-rdf-syntax-ns#",
       "rdfs": "http://www.w3.org/2000/01/rdf-schema#",
+      "skos": "http://www.w3.org/2004/02/skos/core#",
       "sssom": "http://w3id.org/sssom/",
       "@vocab": "http://w3id.org/sssom/",
       "confidence": {
@@ -20,6 +21,14 @@
       "information_content_mica_score": {
          "@type": "xsd:double"
       },
+      "mapping_cardinality": {
+         "@context": {
+            "@vocab": "@null",
+            "text": "skos:notation",
+            "description": "skos:prefLabel",
+            "meaning": "@id"
+         }
+      },
       "mapping_set_id": {
          "@type": "@id"
       },
diff --git a/schema/sssom.external.context.jsonld b/schema/sssom.external.context.jsonld
index 7b7bf49c..9d19ff31 100644
--- a/schema/sssom.external.context.jsonld
+++ b/schema/sssom.external.context.jsonld
@@ -1145,6 +1145,7 @@
         "wb": "https://www.wormbase.org/get?name=",
         "wb.rnai": "https://www.wormbase.org/species/c_elegans/rnai/",
         "wd": "http://www.wikidata.org/entity/",
+        "webelements": "https://www.webelements.com/",
         "wgs84": "http://www.w3.org/2003/01/geo/wgs84_pos#",
         "wikidata": "http://www.wikidata.org/entity/",
         "wikidata.property": "https://www.wikidata.org/wiki/Property:",
diff --git a/schema/sssom.graphql b/schema/sssom.graphql
index 5dcb8e07..dc8e4c05 100644
--- a/schema/sssom.graphql
+++ b/schema/sssom.graphql
@@ -25,7 +25,7 @@ type Mapping
     objectSource: String
     objectSourceVersion: String
     mappingProvider: String
-    mappingCardinality: String
+    mappingCardinality: MappingCardinalityEnum
     mappingTool: String
     mappingDate: String
     confidence: Double
diff --git a/schema/sssom.owl b/schema/sssom.owl
index ea637a98..33c15420 100644
--- a/schema/sssom.owl
+++ b/schema/sssom.owl
@@ -12,11 +12,11 @@
     rdfs:subClassOf [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/mapping_provider> ],
+            owl:onProperty <http://w3id.org/sssom/license> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/subject_source_version> ],
+            owl:onProperty <http://w3id.org/sssom/mapping_set_description> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
@@ -24,66 +24,66 @@
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/mapping_date> ],
+            owl:onProperty <http://w3id.org/sssom/mapping_tool> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
-            owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/other> ],
+            owl:onClass <http://w3id.org/sssom/Entity> ;
+            owl:onProperty <http://w3id.org/sssom/creator_id> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/license> ],
-        [ a owl:Restriction ;
-            owl:maxQualifiedCardinality 1 ;
-            owl:onClass <http://w3id.org/sssom/Entity> ;
-            owl:onProperty <http://w3id.org/sssom/object_match_field> ],
+            owl:onProperty <http://w3id.org/sssom/creator_label> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/see_also> ],
+            owl:onProperty <http://w3id.org/sssom/mapping_provider> ],
+        [ a owl:Restriction ;
+            owl:allValuesFrom <http://w3id.org/sssom/Mapping> ;
+            owl:onProperty <http://w3id.org/sssom/mappings> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
-            owl:onClass <http://w3id.org/sssom/Entity> ;
-            owl:onProperty <http://w3id.org/sssom/subject_match_field> ],
+            owl:onClass linkml:String ;
+            owl:onProperty <http://w3id.org/sssom/comment> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/mapping_set_description> ],
+            owl:onProperty <http://w3id.org/sssom/subject_source_version> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/mapping_tool> ],
+            owl:onProperty <http://w3id.org/sssom/subject_source> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/match_term_type> ],
+            owl:onProperty <http://w3id.org/sssom/mapping_date> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
             owl:onProperty <http://w3id.org/sssom/object_preprocessing> ],
         [ a owl:Restriction ;
-            owl:allValuesFrom <http://w3id.org/sssom/Mapping> ;
-            owl:onProperty <http://w3id.org/sssom/mappings> ],
+            owl:maxQualifiedCardinality 1 ;
+            owl:onClass <http://w3id.org/sssom/Entity> ;
+            owl:onProperty <http://w3id.org/sssom/subject_match_field> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/creator_label> ],
+            owl:onProperty <http://w3id.org/sssom/mapping_set_version> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/subject_preprocessing> ],
+            owl:onProperty <http://w3id.org/sssom/match_term_type> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/comment> ],
+            owl:onProperty <http://w3id.org/sssom/see_also> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
-            owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/object_source> ],
+            owl:onClass <http://w3id.org/sssom/Entity> ;
+            owl:onProperty <http://w3id.org/sssom/object_match_field> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/subject_source> ],
+            owl:onProperty <http://w3id.org/sssom/other> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass <http://w3id.org/sssom/Entity> ;
@@ -91,11 +91,11 @@
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/mapping_set_version> ],
+            owl:onProperty <http://w3id.org/sssom/subject_preprocessing> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
-            owl:onClass <http://w3id.org/sssom/Entity> ;
-            owl:onProperty <http://w3id.org/sssom/creator_id> ] ;
+            owl:onClass linkml:String ;
+            owl:onProperty <http://w3id.org/sssom/object_source> ] ;
     skos:definition "Represents a set of mappings" .
 
 <http://w3id.org/sssom/equivalent_property> a owl:ObjectProperty,
@@ -127,11 +127,11 @@
     dcterms:license "https://creativecommons.org/publicdomain/zero/1.0/" ;
     rdfs:seeAlso "https://github.com/OBOFoundry/SSSOM" ;
     skos:definition "Datamodel for Simple Standard for Sharing Ontology Mappings (SSSOM)" ;
-    linkml:generation_date "2021-06-17 16:27" ;
+    linkml:generation_date "2021-06-22 10:25" ;
     linkml:metamodel_version "1.7.0" ;
     linkml:source_file "sssom.yaml" ;
-    linkml:source_file_date "Thu Jun 17 16:25:04 2021" ;
-    linkml:source_file_size 9957 .
+    linkml:source_file_date "Tue Jun 22 10:23:38 2021" ;
+    linkml:source_file_size 10114 .
 
 <http://w3id.org/sssom/scope> a owl:ObjectProperty,
         linkml:SlotDefinition ;
@@ -295,7 +295,7 @@ linkml:Uriorcurie a owl:Class,
 <http://w3id.org/sssom/mapping_cardinality> a owl:ObjectProperty,
         linkml:SlotDefinition ;
     rdfs:label "mapping_cardinality" ;
-    rdfs:range linkml:String ;
+    rdfs:range <http://UNKNOWN.org/mapping_cardinality_enum> ;
     skos:definition "A string indicating whether this mapping is from a 1:1 (the subject_id maps to a single object_id), 1:n (the subject maps to more than one object_id), n:1, 1:0, 0:1 or n:n group. Note that this is a convenience field that should be derivable from the mapping set." .
 
 <http://w3id.org/sssom/mapping_set_description> a owl:ObjectProperty,
@@ -405,49 +405,37 @@ linkml:Uriorcurie a owl:Class,
         linkml:ClassDefinition ;
     rdfs:label "mapping" ;
     rdfs:subClassOf [ a owl:Restriction ;
-            owl:maxQualifiedCardinality 1 ;
-            owl:onClass <http://w3id.org/sssom/Entity> ;
-            owl:onProperty <http://w3id.org/sssom/object_match_field> ],
-        [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/predicate_label> ],
-        [ a owl:Restriction ;
-            owl:maxQualifiedCardinality 1 ;
-            owl:onClass <http://w3id.org/sssom/Entity> ;
-            owl:onProperty <http://w3id.org/sssom/subject_id> ],
-        [ a owl:Restriction ;
-            owl:maxQualifiedCardinality 1 ;
-            owl:onClass linkml:Double ;
-            owl:onProperty <http://w3id.org/sssom/semantic_similarity_score> ],
+            owl:onProperty <http://w3id.org/sssom/creator_label> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/mapping_tool> ],
+            owl:onProperty <http://w3id.org/sssom/mapping_date> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/see_also> ],
+            owl:onProperty <http://w3id.org/sssom/match_string> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
-            owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/object_preprocessing> ],
+            owl:onClass linkml:Double ;
+            owl:onProperty <http://w3id.org/sssom/information_content_mica_score> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/subject_category> ],
+            owl:onProperty <http://w3id.org/sssom/license> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/object_label> ],
+            owl:onProperty <http://w3id.org/sssom/subject_source> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/match_string> ],
+            owl:onProperty <http://w3id.org/sssom/object_source> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/object_category> ],
+            owl:onProperty <http://w3id.org/sssom/object_preprocessing> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
@@ -455,83 +443,95 @@ linkml:Uriorcurie a owl:Class,
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/license> ],
+            owl:onProperty <http://w3id.org/sssom/object_category> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/object_source> ],
+            owl:onProperty <http://w3id.org/sssom/see_also> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/subject_source> ],
+            owl:onProperty <http://w3id.org/sssom/object_label> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass <http://w3id.org/sssom/Entity> ;
-            owl:onProperty <http://w3id.org/sssom/object_id> ],
+            owl:onProperty <http://w3id.org/sssom/predicate_id> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass <http://w3id.org/sssom/Entity> ;
             owl:onProperty <http://w3id.org/sssom/creator_id> ],
+        [ a owl:Restriction ;
+            owl:maxQualifiedCardinality 1 ;
+            owl:onClass linkml:Double ;
+            owl:onProperty <http://w3id.org/sssom/semantic_similarity_score> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/match_type> ],
+            owl:onProperty <http://w3id.org/sssom/subject_label> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/other> ],
+            owl:onProperty <http://w3id.org/sssom/comment> ],
+        [ a owl:Restriction ;
+            owl:maxQualifiedCardinality 1 ;
+            owl:onClass <http://w3id.org/sssom/Entity> ;
+            owl:onProperty <http://w3id.org/sssom/subject_id> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/mapping_provider> ],
+            owl:onProperty <http://w3id.org/sssom/object_source_version> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/comment> ],
+            owl:onProperty <http://w3id.org/sssom/subject_source_version> ],
+        [ a owl:Restriction ;
+            owl:maxQualifiedCardinality 1 ;
+            owl:onClass <http://UNKNOWN.org/mapping_cardinality_enum> ;
+            owl:onProperty <http://w3id.org/sssom/mapping_cardinality> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/subject_label> ],
+            owl:onProperty <http://w3id.org/sssom/match_type> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass <http://w3id.org/sssom/Entity> ;
             owl:onProperty <http://w3id.org/sssom/subject_match_field> ],
+        [ a owl:Restriction ;
+            owl:maxQualifiedCardinality 1 ;
+            owl:onClass linkml:String ;
+            owl:onProperty <http://w3id.org/sssom/predicate_label> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass <http://w3id.org/sssom/Entity> ;
-            owl:onProperty <http://w3id.org/sssom/predicate_id> ],
+            owl:onProperty <http://w3id.org/sssom/object_id> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
-            owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/mapping_cardinality> ],
+            owl:onClass linkml:Double ;
+            owl:onProperty <http://w3id.org/sssom/confidence> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/object_source_version> ],
+            owl:onProperty <http://w3id.org/sssom/subject_category> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
             owl:onProperty <http://w3id.org/sssom/match_term_type> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
-            owl:onClass linkml:Double ;
-            owl:onProperty <http://w3id.org/sssom/information_content_mica_score> ],
+            owl:onClass <http://w3id.org/sssom/Entity> ;
+            owl:onProperty <http://w3id.org/sssom/object_match_field> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/mapping_date> ],
-        [ a owl:Restriction ;
-            owl:maxQualifiedCardinality 1 ;
-            owl:onClass linkml:Double ;
-            owl:onProperty <http://w3id.org/sssom/confidence> ],
+            owl:onProperty <http://w3id.org/sssom/mapping_tool> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/subject_source_version> ],
+            owl:onProperty <http://w3id.org/sssom/other> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/creator_label> ] ;
+            owl:onProperty <http://w3id.org/sssom/mapping_provider> ] ;
     skos:definition "Represents an individual mapping between a pair of entities" ;
     skos:exactMatch owl:Axiom .
 
@@ -685,21 +685,21 @@ linkml:topValue a owl:DatatypeProperty ;
         linkml:ClassDefinition ;
     rdfs:label "entity" ;
     rdfs:subClassOf [ a owl:Restriction ;
-            owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/source> ],
+            owl:onProperty <http://w3id.org/sssom/id> ;
+            owl:qualifiedCardinality 1 ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/category> ],
+            owl:onProperty <http://w3id.org/sssom/source> ],
         [ a owl:Restriction ;
             owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
             owl:onProperty <http://w3id.org/sssom/label> ],
         [ a owl:Restriction ;
+            owl:maxQualifiedCardinality 1 ;
             owl:onClass linkml:String ;
-            owl:onProperty <http://w3id.org/sssom/id> ;
-            owl:qualifiedCardinality 1 ] ;
+            owl:onProperty <http://w3id.org/sssom/category> ] ;
     skos:definition "Represents any entity that can be mapped, such as an OWL class or SKOS concept" ;
     skos:exactMatch rdf:Resource .
 
diff --git a/schema/sssom.shex b/schema/sssom.shex
index 96e7b021..caac1051 100644
--- a/schema/sssom.shex
+++ b/schema/sssom.shex
@@ -60,7 +60,7 @@ linkml:Nodeidentifier NONLITERAL
           <object_source> @linkml:String ? ;
           <object_source_version> @linkml:String ? ;
           <mapping_provider> @linkml:String ? ;
-          <mapping_cardinality> @linkml:String ? ;
+          <mapping_cardinality> @<MappingCardinalityEnum> ? ;
           <mapping_tool> @linkml:String ? ;
           <mapping_date> @linkml:String ? ;
           <confidence> @linkml:Double ? ;
diff --git a/schema/sssom.yaml b/schema/sssom.yaml
index 97c8e068..6201faac 100644
--- a/schema/sssom.yaml
+++ b/schema/sssom.yaml
@@ -13,6 +13,17 @@ default_curi_maps:
 - semweb_context
 - obo_context
 default_prefix: sssom
+
+enums:
+  mapping_cardinality_enum:
+    permissible_values:
+      "1:1":
+      "1:n":
+      "n:1":
+      "1:0":
+      "0:1":
+      "n:n":
+
 slots:
   entity_field:
     abstract: true
@@ -145,7 +156,7 @@ slots:
       maps to a single object_id), 1:n (the subject maps to more than one object_id), 
       n:1, 1:0, 0:1 or n:n group. Note that this is a convenience field that should be derivable 
       from the mapping set.
-    range: string
+    range: mapping_cardinality_enum
   mapping_tool:
     description: A reference to the tool or algorithm that was used to generate the
       mapping. Should be a URL pointing to more info about it, but can be free text.
diff --git a/schema/sssom_datamodel.py b/schema/sssom_datamodel.py
index b57fe048..4796aa5c 100644
--- a/schema/sssom_datamodel.py
+++ b/schema/sssom_datamodel.py
@@ -1,5 +1,5 @@
 # Auto generated from sssom.yaml by pythongen.py version: 0.9.0
-# Generation date: 2021-06-17 16:27
+# Generation date: 2021-06-22 10:24
 # Schema: sssom
 #
 # id: http://w3id.org/sssom/schema/
@@ -184,7 +184,7 @@ class Mapping(YAMLRoot):
     object_source: Optional[str] = None
     object_source_version: Optional[str] = None
     mapping_provider: Optional[str] = None
-    mapping_cardinality: Optional[str] = None
+    mapping_cardinality: Optional[Union[str, "MappingCardinalityEnum"]] = None
     mapping_tool: Optional[str] = None
     mapping_date: Optional[str] = None
     confidence: Optional[float] = None
@@ -252,8 +252,8 @@ def __post_init__(self, *_: List[str], **kwargs: Dict[str, Any]):
         if self.mapping_provider is not None and not isinstance(self.mapping_provider, str):
             self.mapping_provider = str(self.mapping_provider)
 
-        if self.mapping_cardinality is not None and not isinstance(self.mapping_cardinality, str):
-            self.mapping_cardinality = str(self.mapping_cardinality)
+        if self.mapping_cardinality is not None and not isinstance(self.mapping_cardinality, MappingCardinalityEnum):
+            self.mapping_cardinality = MappingCardinalityEnum(self.mapping_cardinality)
 
         if self.mapping_tool is not None and not isinstance(self.mapping_tool, str):
             self.mapping_tool = str(self.mapping_tool)
@@ -336,7 +336,26 @@ def __post_init__(self, *_: List[str], **kwargs: Dict[str, Any]):
 
 
 # Enumerations
-
+class MappingCardinalityEnum(EnumDefinitionImpl):
+
+    _defn = EnumDefinition(
+        name="MappingCardinalityEnum",
+    )
+
+    @classmethod
+    def _addvals(cls):
+        setattr(cls, "1:1",
+                PermissibleValue(text="1:1") )
+        setattr(cls, "1:n",
+                PermissibleValue(text="1:n") )
+        setattr(cls, "n:1",
+                PermissibleValue(text="n:1") )
+        setattr(cls, "1:0",
+                PermissibleValue(text="1:0") )
+        setattr(cls, "0:1",
+                PermissibleValue(text="0:1") )
+        setattr(cls, "n:n",
+                PermissibleValue(text="n:n") )
 
 # Slots
 class slots:
@@ -427,7 +446,7 @@ class slots:
                    model_uri=SSSOM.mapping_provider, domain=None, range=Optional[str])
 
 slots.mapping_cardinality = Slot(uri=SSSOM.mapping_cardinality, name="mapping_cardinality", curie=SSSOM.curie('mapping_cardinality'),
-                   model_uri=SSSOM.mapping_cardinality, domain=None, range=Optional[str])
+                   model_uri=SSSOM.mapping_cardinality, domain=None, range=Optional[Union[str, "MappingCardinalityEnum"]])
 
 slots.mapping_tool = Slot(uri=SSSOM.mapping_tool, name="mapping_tool", curie=SSSOM.curie('mapping_tool'),
                    model_uri=SSSOM.mapping_tool, domain=None, range=Optional[str])