Doing Warrior I

I am confused as to whether the heel of the straight leg should be on or off the floor when doing Warrior I in sun salutations. I go to classes by different teachers, some teachers teach that the feet of the straight leg should be turned outward 90 degrees with heel planted firmly on the floor. Other teachers teach that the feet should be turned 45 degrees and heel should be up. I was told that these are 2 different poses. Can someone please tell me which is the orthodox way? Thanks!