Do an Entity and Relationship require a crosswalk and values associated with it?
An entity requires at least one crosswalk that has both a named source and value.
A relationship must have a crosswalk with a named source but does not require a value.
Reltio associates each value for any attribute in an entity or in a relationship with a data source. This is done via a crosswalk which is defined against an entity or relationship.
It is important to preserve the uniqueness of a crosswalk.