[angry_octet]

Where do they draw the line? Is a person with a PhD in physics who writes analytics software credited? Or only someone with an official research program/grant?

It seems that there can't be that many people actively involved in the paper, but everyone needs to be on, e.g. the Higgs boson paper, not referenced in a supporting work on, e.g. a detector, or their career is trashed.

In our lab we always push for people to write up what they are working on, which may or may not be 'original'. Usually it turns out that there is much innovative or original work, which without documentation the experiment could not be repeated/analysis would have been different, etc. And that kind of tech note/report should be referenced by all the experiments that tool/technique, even if they are not co-authors of the derived work. For example, an experimenter uses visualisation system Y in producing report X: X->Y reference. The vis system uses FFTW documented in report Z: Y->Z. The source and binaries and build chain for the expt and analysis are in VM images archived with the data.