I never heard anybody mention this in this forum before, is this a must, if so, what should I say?
I google search, found an example like following, is this good?
"I am applying for Advance Parole in order to be able to visit my family in Country X. In particular my parents are both elderly and I would like to be able to visit at short notice if either of them were to be become dangerously ill"
Thanks a lot for your sharing