I have a bibliography file which contains definitions in the journal name field, for example \pra, and I define this in my file as \def \pra {Phys. Rev. A}, which is what I want for my bibliography.
Now I would also like to be able to have a command like \citearticleshort or something, which would insert a shorthand for the journal name, for example PRA in this case, plus volume number and possibly page.
How can I get \pra to expand to Phys. Rev. A in one case and PRA in another case? I saw there is something like mapping in biblatex, but I couldn't figure out how to use it to solve my problem.

biblatex), butbiblatexprovides\ifcitationand\ifbibliographythat are true only if we are currently in a citation or in the bibliography, respectively. So you might do\newcommand*{\pra}{\ifcitation{PRA}{Phys. Rev. A}}. Of course you also might use a completely custom toggle here, but then you need to be more specific as to when what is to appear. (Not tested for lack of an MWE.) – moewe Feb 23 '15 at 07:15