make ghostwriting almost legitimate
http://plosmedicine.org/article/info:doi/10.1371/journal.pmed.1001084#article1.body1.sec1.p4

This is one of the places where a definition of ghostwriting would be so important. If we take the definition that a ghost is invisible (my definition, and, I believe, the majority one), then I don't think anyone is trying to claim that ghostwriting is legitimate. If, however, you believe that a medical writer whose role is transparently described in an acknowledgements section is ghostwriting, then it is the ICMJE guidelines themselves that give this practice legitimacy.