As a new R-Pi user, I was surprised to find that there was absolutely no documentation with the IoT pHAT. Visiting this site also contains no clues on how to proceed! Reading the Blog was no help either - it assumes pre-knowledge. I eventually found the documentation under GitHub… not an obvious choice.
Adding a tab to the home page called ‘Dowloads/Docs’ which merely says (or directs to the GitHub would solve that. problem.
(It also isn’t obvious how to add topics to the forum, but that’s another point.)