I do remember one rule that came from a supplement to the little white bible that pertained to conduct at the Missionary Training Center (MTC) in Provo, Utah. “Always pass the pepper with the salt.” I must have been about 4 weeks in to my stay at the MTC when I stumbled across this commandment. Always pass the pepper with the salt. This here, this is divine inspiration.
The funny thing is, the reason for this rule was probably just so that the MTC cafeteria folks could keep the salt and pepper together, so that the shakers wouldn't get separated or something. I can imagine someone in charge of cafeteria requisition complaining to the MTC president that they keep losing individual shakers and having to replace them. So, to cut costs, the powers-that-be invent the rule, which conveniently in Mormonism translates a random need of the church into a Commandment of God.
Or maybe someone higher up just thought it was bad manners for missionaries to pass one without the others, and he complained about it to the MTC president. Who knows? It could have been any one of a number of burrs-up-the-ass that Mormon leaders get lodged in there from time to time.