Both halves are strings, because the padding is part of how a Land writes it and
it is not ours to normalise: Thüringen's records carry 08/980 while the
document itself says 8/980. An earlier version made period a number "because
leading zeros are part of how a Land prints it" — which was true, and then
dropped the zero from the only half that had one, so formatReference did not
round-trip. periodNumber is there for the callers that want to compare.
A Drucksachennummer, as printed.
Both halves are strings, because the padding is part of how a Land writes it and it is not ours to normalise: Thüringen's records carry
08/980while the document itself says8/980. An earlier version madeperioda number "because leading zeros are part of how a Land prints it" — which was true, and then dropped the zero from the only half that had one, soformatReferencedid not round-trip.periodNumberis there for the callers that want to compare.