A "naming system" is really just a way to label images of Abraham Lincoln (and
sometimes other Lincolns). Lots of systems are possible, for example sequential
numbering, or chronological naming. Over times, different authorities have used
different naming systems, and this can cause confusion. We decided to present all known
naming systems of reasonably repute on this web site, to help readers de-code
references, no matter which naming system and authority might use.