[michaelhoffman]

I like the four-document model. While it isn't a perfect fit for all cases, for many it is a good start.

We wrote a review of bioinformatics software documentation, which includes a taxonomy of research software documentation (Table 1) and examples of which popular bioinformatics software packages use each two (Table 2). It is clear that not every kind is needed for everything, and it's more of a menu than a prescriptive set of documentation types needed for everything:

https://academic.oup.com/bib/article/19/4/693/2907814