My question doesn't actually.

Hi,
My question doesn't actually concern any car, its a recurring doubt whose answer I haven't found as of yet.
Is there any rule of mounting the brake calipers on the front wheels?
I mean, Can I mount the calipers on both rotors in the same position if we look from the side (like both at the top) or the calipers have to be offset to eachother by some angle, again if we look from the side.
I hope you shed some light
Thanks
Chitrarth