I see the "rules" a bit differently, LOL!
1. Never argue with the regulars on the NI board, even when they visit another board, that crowd believes only they have the right way and the truth on every subject, whether they actually know anything about it or not.
2. Don't admit you are showing koi from a domestic USA breeder at a koi show if you want to have a chance of winning your class.
3. If you take a koi to a show, don't admit you practice any technology for koi keeping except the technology that the judges for that show thinks is the best way (meaning what is running in their own ponds).
4. Never admit nor discuss the huge losses to the KHV virus that have run rampant through the USA koi hobby for the last 6 years in a row.
5. Pretend you did not read about millions of pounds of carp died in Japan from the KHV virus.
6. Pretend you did not notice the All Japan koi show had to be cancelled for fear of spreading the KHV virus.
7. Pretend you did not read about the verified reports of KHV kills of carp in some wild rivers in the USA.
There are a lot of other unwritten rules of the hobby, but I better stop here before I get personal in my comments!