Controlled Vocabularies vs. Ontological Modelling

Angina (Canadian class 0 to IV) (more severe)

Galen models Angina classifications (and severity) explicitely:

     :AnginaPectoris owl:intersectionOf (
       :ChestPain
       [
         a owl:Restriction;
         owl:onProperty :isSpecificImmediateConsequenceOf;
         owl:someValuesFrom :MyocardialIschaemiaLesion.
       ] 
     )

    :AnginaClassI rdfs:subClassOf :AnginaPectoris.
    :AnginaClassII rdfs:subClassOf :AnginaPectoris.
    :AnginaClassIII rdfs:subClassOf :AnginaPectoris.
    :AnginaClassIV rdfs:subClassOf :AnginaPectoris.

    StableAngina owl:intersectionOf (
      :AnginaPectoris 
      [
        a owl:Restriction;
        owl:onProperty :hasSeverity;
        owl:someValuesFrom [
          ... complex structure ...
        ]
      ]
    )