3) A detailed test plan. When I say "detailed," I mean that it should include enough detail that it could be followed by someone familiar with Koha who does not use whatever section of the code you are editing. A test plan with forty steps may seem daunting, but it really isn't. It's considerate. Ideally, the test plan should cover how to confirm the bug *and* how to confirm that the patch fixed the problem, if the two procedures are not entirely identical (for example, if your patch involves Zebra configuration changes, note which files need to be updated; I favor a tl;dr section which includes information of this sort).