It isn't duplicated - it's just suggested for re-use.

On Thu, Jul 14, 2011 at 3:48 PM, Gregor Hagedorn <g.m.hagedorn@gmail.com> wrote:
>> Although these three terms are in the DCMI type vocabulary, the DCMI
>> type vocabulary does not provide the controlled values for
>> basisOfRecord, so they need to be in the DwC type vocabulary.

Question to an RDF-expert: Is this a technical limitation? I don't
fully grasp why here a vocabulary needs to duplicated (the entire
dcmi-type vocabulary is a potential vocabulary for basis of record,
not just three items).

Gregor