This has always made me wonder. Black pepper is so ubiquitous and innocuous. It is called for in so many recipes.
When do you not want to mix pepper flavors or when do you commonly mix them?
An example would be black pepper and cayenne; it seems common. Black pepper with chipotles? Chili powder and black pepper? Seems like some pepper flavors might fight or that you might not want to add black pepper, on occasion, so others flavors would be more up front.
Then there is the size of the pepper component: fine ground versus coarse or cracked black peppercorns. Smashed green (or black), peppercorns and chunks of jalapeno versus ground, where it can be totally infused or you get bursts of flavor.... and whether you add it early or late (or when it's served).
Are there any rules?