Surprisingly enough, there are just three regulations to be observed in regards to those going in search of the Yeti. The first stipulation is that you have to purchase a permit from the government of Nepal for 5000 Indian Rupees before setting out on your expedition. That's roughly $108 by today's exchange rate, a relative bargain in terms of big game hunting.
Secondly, if you do manage to come across a Yeti, it can only be photographed or captured alive. It is forbidden to kill the legendary creature unless it is in self defense. Live specimens or photos of the beast are to be turned over to the Government of Nepal as soon as possible.
Finally, it is forbidden to share any news or reports substantiating the existence of the Yeti with the press without first receiving permission from the Government of Nepal. Any such reports should first be turned over to the government before submitting them to the press or a reporter.
Reading through this memo I got a chuckle out of the fact that it is a real document handed out by the U.S. government to anyone heading into the Himalaya looking for the Abominable Snowman. It makes you wonder what other memos are out there floating around, such as Regulations for First Contact with Alien Lifeforms or How to Approach a Sasquatch. Either way, I found it to be a fun and interesting slice of history.