Right on the money.
However, I don't know how well a hybrid would survive. I haven't seen or heard of many, so I assume there are issues.
Rat snakes are a grouping of tons of different snakes.
Here: http://en.wikipedia.org/wiki/Rat_snake it explains many of the different branches and 'types' of rat snakes out there, one of them includes corn snakes. ;]
Edit: Also fantastic looking white sided! Others that I have seen pictures of are not nearly as beautiful as that!