PO Population

(a limit field)

human in po

po=female

The PO field indicates the classification of population the record concerns, such as human, animal, female, male, inpatient, outpatient. A record can contain up to 6 population groups. Records contain consistent population terms beginning in 1998. Most records prior to 1967 do not contain this field. You can search using the field label (PO) or from the Population Index described below.

Browsing Population Classifications

As an alternative to searching with the field label, you can browse population classifications and search for them directly from the Population Field-Specific Index. This field-specific index contains only population classifications drawn from the PO field, therefore, your search will always yield results. Search results display in the PO field.