10/26/09: This defined class is used as a 'macro expression' to reduce the size of the IEDB export
2010/02/24 Alan Ruttenberg: I think this might generate confusion as the common use of the term would consider something to be a specimen during the realization of the role, not only if it bears it. However having this class as a probe, or for display, or as a macro might be useful. Ideally we would mark or segregate such classes