Real co-first authors? I notice that in the physics field, there are sometimes co-first authors, both names being followed by a footnote saying "These two authors contribute equally."

Even though explicitly labeled as so, one name still comes before the other. Also, as far as I know, the one believed to contribute a little bit more goes first. Hence, these are actually not real co-first authors.

Imagine in some journal with an author-title header on every page. The name of FirstAuthorB, the co-first author who comes after FirstAuthorA, will not be shown, as in


  FirstAuthorA et al.: Paper Title


So is there some other generally accepted ways to truly display two first authors as completely equal?
Within normal procedures the best way would be to list the two first authors in alphabetical order and then make a statement in the acknowledgement that the two have contributed equally. In this we assume that the way authorship is distributed in falling order. Many journals now also ask for a specification of contributorship of all authors to distinguish who has done what. One oddity I cam across was a paper by K &amp; H (last name initials) where it was listed in the acknowledgement that both had contributed equally. In this case H was the PhD student of K and so K may have wanted the primary spot to get the full impact of the prestigious publication.

So the way to signal contributions by ordering authors is not without its problems. But, most of the problems come from the fact that first authorship is used without discretion to assign merit. So from this perspective it is a result of a flawed system. Attributing contributorship can even out the playing field to some extent but basically we will have to live with the systems. One should also remember that the most important aspect of the reference for most is the sourcing of information, not who did what. So an example of how a system built for one purpose has been adopted to solve another.