Cartesian movements standard?

The Pronterface home is not the same direction as the plus and minus movements.
Is this normal? I realize I can the directions in the firmware but plus is supposed to up and away.
Or which way is correct before I try to print?
What standards do I synchronize to?

For a Cartesian there are two options to home:
Front / Left corner
or
Rear / Right corner ( my favorite because the bed is accessible after homing )

But don't get confused by rear / right on a Prusa i3. The bed will move to the front where the endstop should be. From the nozzles point of view it is zero then.
-Olaf

Edited 1 time(s). Last edit at 12/03/2015 03:34AM by o_lampe.

I forgot that I moded this and forgot to mention that I put the y axis min stop in the rear.
I set the directions to Mendel at it worked. The Prusa i3 has that min stop in the front.