Relation dc#Type (?,pm#entity)  to specify the nature or genre of the content of a resource; SHOULD NOT BE USED IN WEBKB
  exclusion:  dc#Description
  subtype:  sumo#instance (pm)  if the common reading conventions of parameters had been respected, this type would have been named instance_of; an object is an instance of a set_or_class if it is included in that set_or_class; an individual may be an instance of many classes, some of which may be subclasses of others; thus, there is no assumption in the meaning of instance about specificity or uniqueness
  supertype:  pm#binary_relation (?,?)  in WebKB, most relation types are binary and some have a variable number of arguments (as in KIF), hence this type is currently only specialized by types that I do not want to see as direct subtypes of pm#relation
     supertype:  pm#relation_with_particular_property (*)  this rather fuzzy type permits to group categorization schemes less common than those covered by the previous sibling categories
        >part of:  pm#relation__related_thing__relatedthing___related_with  type for any relation (unary, binary, ..., *-ary) and instance of pm#relation_type