ContactKey Field

DefinitionThis is the foreign key relating to the Contact Resource. A unique identifier for this record from the immediate source. This is a string that can include a Uniform Resource Identifier (URI) or other forms. This is the local key of the system. When records are received from other systems, a local key is commonly applied. If conveying the original keys from the source or originating systems, see SourceSystemKey and OriginatingSystemKey variants.