A strong PIN does not contain personal info, such as your date of birth  or address. It should be a number only you know and can’t be easily guessed.
PIN iǧehden ulac deg-s talɣutin tudmawanin, am wazemz n tlalit-ik  neɣ tansa-ik. Yewwi-d ad yili d uṭṭun i tessneḍ kan keččini rnu ad yiwεiṛ i tiftin.