external_identifier

Tag	Data Type	Required?	Repeats?	Description	Error Handling
type	identifier_type	Required	Single	Specifies the type of identifier. Must be one of the valid types as defined by identifier_type.
other_type	xs:string	Optional	Single	Allows for cataloging an ExternalIdentifier type that falls outside the options listed in identifier_type. Type should be set to “other” when using this field.
value	xs:string	Required	Single	Specifies the identifier.