What Does The X On Wal-mart Receipt What Does The X, Y, And R Mean On The Right Side Of A Wal-mart Receipt?

What does the X, Y, and R mean on the right side of a Wal-mart receipt? - what does the x on wal-mart receipt

I'm trying to understand how my tax money to pay for food, and I do not know what the letters on the right side of the front