I have my own company. I am literally the captain. The guidelines are very loose. Don’t get so shitfaced or stoned that you become a danger to yourself, others, or the vessel. Often, once we leave the harbor, ship’s company will lose their clothes. The rule there is consent and permission. If any act is perpetrated on a person without consent or permission, I will bring the individual or individuals up on charges, radio ahead, and have the cops waiting for them at the dock. Basically, those are the guidelines.
I work for the government. There are no rules for socializing as we’re all adults and we are free to behave like adults. We have the law over us as far as sexual harassment, violence, etc. like all citizens but nothing specific to socializing with people higher or lower.
The (unwritten) rules are the consultant with the biggest private practice pays for the drinks. The nurse that goes home with them doesn’t talk about it.
Most companies do not have rules about that but do expect their employees, who are adults by the way, to behave appropriately. Some companies do prohibit fraternizing/dating between employees. Some will not allow both spouses in a marriage to work for the company and if they marry while both employed, one must resign.