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SIP ID (mandatory) - Identifier of the delivered SIP within the context of the given Producer-Archive Project. If there are multiple Producer Sources submitting SIPs within a single Producer-Archive Project, this SIP ID must be unique across all such Producer Sources. It is inserted during SIP construction. The form shall be agreed between Producer and Archive, but the identifier shall be generated by the Producer. The Archive shall check uniqueness.
Producer-Archive Project ID (mandatory) - Identifier of the Producer-Archive Project that distinguishes the project from all other Producer-Archive Projects undertaken by this Archive. This ID shall be provided by the Archive for use in the SIPs (see also first paragraph PAIS section 3).
SIP Content Type ID (mandatory) - Identifier of the specification that defines which Transfer Object Types (i.e., Descriptor IDs) are allowed within this SIP, as well as their occurrence within the SIP. It has been defined previously in this document (see PAIS section 4).
SIP Sequence Number (optional) - Number indicating the order in which the SIP has been sent. This number is unique within the combined context of the Producer-Archive Project and Producer Source ID. This becomes mandatory for all SIPs sent by a Producer Source if any of the Transfer Objects to be provided by the Producer Source have a Descriptor that does not specify a unique value for the number of Transfer Objects to be delivered. It shall be generated by the Producer.
Any (optional) - Mechanism that allows a SIP to have any additional attributes within the structure of the SIP corresponding to this container.
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