Each entity type in CubicWeb has at least the following meta-data attributes and relations:
entity’s identifier which is unique in an instance. We usually call this identifier eid for historical reason.
Date and time of the creation of the entity.
Date and time of the latest modification of an entity.
Reference URL of the entity, which is not expected to change.
Relation to the users who has created the entity
Relation to users whom the entity belongs; usually the creator but not necessary, and it could have multiple owners notably for permission control
Relation to the entity type of which type the entity is.
Relation to the entity types of which type the entity is an instance of.