Thank you Nick. That's the one I was trying to find.
This is what got me in A. O. Smith's response "Otherwise there could be rusting of the bottom of the unit." - DUH! Why to heck do you think I've been trying to get a straight answer from you guys and gals - do you or do you not allow them to be installed where they can set in water, i.e., be partially submerged!
The answers I am getting are beating around that bush - I suspect they never considered that "water" would actually get in a drain pan intended to collect "water"?
Now that it's been pointed out, I wonder what they will do?