Card

In std/doc.

abstract type Card : Doc { metadata : Data // the knowledge attached to this card, assembled kind : String // "ConceptCard" or "RelationCard" }

A card: knowledge given a physical document, the document a vault holds. Its metadata is the knowledge attached to it, assembled, and its kind is "ConceptCard" or "RelationCard", the two kinds module knowledge declares, which say what the document is about.