Below is taken from the i.MX6DQ6SDLHDG (Hardware Development Guide for i.MX 6Quad, 6Dual, 6DualLite, 6Solo Families of Applications Processors);
Below is taken from the HW_Design_Cheching_List_for_i.MX6DQP6DQ6SDL_Rev3.1.xlsx
One says the constraint is <=25 while the other says +/-50 mils. Which one to trust? With one my design fails and the other it passes..