How do you know what PID to use for shiny legendaries from DA?

[ivanprimero]

So I read shiny works different in order to be legal with DA mons. Can someone explain me how to do it propperly so that it flags them legal? I attach a Landorus pk8 if needed as example

645 - Landorus - AEB75EC0FC45.pk8

[ReignOfComputer]

PID must be XOR=1. Reroll until it sticks.