General Coat Patterns Questions

So I guess I am here to get clear answers. This does not concern grandfathered characters/puppies that derive from characters with markings approved and in game currently. I am looking to find out what is what is acceptable and what is not when it comes to coat patterns/markings/what have you. Currently, I feel that "semi-realism" is extremely subjective and thus leads to a lot of confusion. I know I, myself, am very hesitant to bring in a character with anything other than a plain coat parttern. I know there are lots of feelings on this but figured I'd make a discussion about the overall topic rather than specific markings/colors.