Relation pm#relation_from_description_content/medium/container (pm#description_content/medium/container,*)
  exclusion:  pm#relation_from_situation  pm#spatial_relation_from_entity_with_spatial_feature  pm#relation_from_collection  pm#relation_from_attribute_or_quality_or_measure
  subtype:  pm#relation_from_description  pm#relation_from_string  pm#version  pm#version_id  dc#Coverage  dc#Contributor  dc#Source  dc#Publisher  dc#Rights  pm#authoring_time  pm#author  dc#Language  dc#Format  pm#description_instrument  pm#description_object  pm#physical_support  pm#rhetorical_relation  pm#argumentation_relation
  supertype:  pm#relation_from/to_thing_of_common_kind (*)  this type permits to categorize relations according to their signatures and hence offers (i) a concise way to set essential exclusion relations, and (ii) a systematic and easy-to-follow categorization
     >part of:  pm#relation__related_thing__relatedthing___related_with  type for any relation (unary, binary, ..., *-ary) and instance of pm#relation_type