Museums, herbaria and members of the research community routinely exchange a diverse array of labelled material -- mounted specimens, microscope slides, DNA samples, photographs, virtual images, sound recordings, etc. Because no standard method of labelling this material exists, keeping track of individual items is inefficient at best and often impossible. Only a small fraction of the estimated 3 billion museum and herbaria specimens are labelled with specimen-level identifiers. Most are simply labelled with the locality, date, and other information associated with their collection -- information that may or may not distinguish each specimen from all others.

Pioneered by the Dan Janzen, Winnie Hallwachs, and the National Institute of Biodiversity in Costa Rica (INBio), progressive collections now label specimens with locally unique barcodes and associate specimen-level information with these unique identifiers in their databases. Thus, they can efficiently keep track of loan status and determination history of individual specimens, for instance. These institutions have typically adopted barcodes encoding a short institutional identifier (e.g., INBIOCRI, UGCA, USNM ENT, or SM) and a locally unique number. Unfortunately, because of the limited number of characters that can fit within small barcodes, these institutional identifiers are, by themselves, too short to guarantee that they are globally unique. SM may identify the specimens of both the Snow Museum and the more ubiquitous, though less famous, Sam Miller. Furthermore, while institutions have generally tried to chose institutional identifiers to avoid duplication based on norms or registries within their discipline, under the current system of self-choice, institutional identifiers could easily be duplicated between disciplines.

To better track labelled material among institutions and to facilitate inter-connectivity across their distributed databases, specimen-level identifiers must be globally, not just locally, unique.