Loans are made to botanical institutions or departments engaged in taxonomic research and postgraduate instruction, and in rare cases to qualified individuals not officially connected with an institution. The head of the borrowing institution assumes responsibility for the safe custody and return of the specimens. For the most part, requests for loans are honored without reservation, both as to size and duration, but WIS requests that specimens be returned at the earliest opportunity, and in the case of large loans, in which difficult taxa may require more time for study, encourages partial returns. There is no charge for the requesting institution or researcher unless special handling or shipping are necessary and agreed upon by both institutions. Loans must not be removed from the borrowing institution, and they may not be transferred from one institution to another without written permission and agreement of all parties concerned.

WetterAll loaned specimens should be annotated as fully as possible before being returned. Annotations should be made on a separate label approximately 2.5 x 10 cm; they should be typewritten or written with indelible ink, never with a ballpoint or felt tip pen; and they should be glued fast to the herbarium sheet, preferably above the original label or near the bottom of the sheet. The annotation should bear the accepted name of the taxon, the name of the investigator, his/her institution, and the date of the identification. If the researcher agrees with the original determination or cannot make a determination, the specimen should be so annotated. Previous annotations should not be altered, and original labels or notes must not be marked, covered, or removed. All TYPE specimens should be annotated with the BASIONYM and citation of the place of publication.

Incomplete labels, especially on older specimens and mounted type photographs, can often be augmented with more complete data from duplicate sheets on loan from other institutions. We encourage researchers to provide any such additional data on a separate slip and attach it to appropriate WIS specimens. We would appreciate this especially when it involves adding the locality, date, collector, or collection number to the specimen.

All University of Wisconsin-Madison/Wisconsin State Herbarium specimens should be cited with the accepted herbarium acronym "WIS" in any published specimen listings. The bar code number is also the WIS accession number and can be cited along with the acronym.