Of the famous five papers Albert Einstein wrote in 1905, the one deriving E = mc2 is not the most cited. The reason is undoubtedly connected to the fact that E = mc2 is all the reference we use when referring to this relationship. A more recent example will prove my point. Kary Mullis’s Nobel Prize paper on polymerase chain reaction may well be the most cited paper of all time. But after a while, authors simply use “PCR method” as shorthand with no reference to the author. Moreover, to the typical citing author, actual use of the PCR method has clearly been of much greater value than the typical reference one cites. Citation theorists have paid insufficient attention to this transmutation of citations to acronyms for the paper. Should they not also be counted?