@reiver This might be a misunderstanding. Any property in ActivityPub can have multiple properties [except the few marked as 'functional'].It does not need a special subtype. If we have type ['CollectionPage', 'Collection', 'wd:Q201456'], it is a directory in a directory (?) We have these nested structures in fedigeo anywhere, for example the UNESCO World Heritage or IATA Collection etc. We use wikidata (the data of wikipedia) so that anyone can use the label and infos for "directory" in any language …