Graduate students in the health sciences who hope to become independent researchers must be able to write up their results at a standard suitable for submission to peer-reviewed journals. Bayesian analyses are still rare in the medical literature, and students are often unclear on what should be included in a manuscript. Whilst there are published guidelines on reporting of Bayesian analyses, students should also be encouraged to think about "why" some items need to be reported whereas others do not. We describe a classroom activity in which students develop their own reporting guideline. The guideline that the students produce is not intended to replace existing guidelines, rather we have found that the process of developing the guideline is helpful in encouraging students to think through the "why?" as well as the "what?" of reporting. (Contains 1 table.)