The value of _struct_ref.id must uniquely identify a record
in the STRUCT_REF list.
Note that this item need not be a number; it can be any unique
identifier.
Additional Descriptive Information for Depositors
The value of _struct_ref.id must uniquely identify
a record in the STRUCT_REF list. Note that this
item need not be a number; it can be any unique
identifier.