White Oak Snake is another common name for a Gray Rat Snake. I think that most of the folks on this forum would take the term to mean a hypo colored natural Gray Rat morph. The ones in the first post are a borwn and tan phase morph. If I remember correctly, Steve C. has a very light gray morph that he got from D.G. that most of us would also think of as a White Oak Snake.
This is a case where a common name has been adopted for hypo colored Gray Rats. It is my understanding that in some areas, American Rat Snakes are called Cow Suckers and in other areas they are know as Chicken Snakes. Most of us just use the most common name in use for these snakes, in this case, Gray Rats, because it is easier to remember, pronounce and spell than the scientific name that still seems to be a moving target.
Gray Rat, White Oak, Gulf Hammock, they are all wonderfull looking American Rats IMHO.