Pakistani’s are almost always Muslim (due to Partition [https://en.m.wikipedia.org/wiki/Partition_of_India]), and will often act and speak differently in several telltale ways for anyone who knows what to look for. Both given and family/surnames are also often telltales.
And if you think Casteism is a bitch, Pakistani/Indian (or Indian Hindu vs Indian Muslim) is a bitch and a half. Just try to apply for a visa for India and see how many times they ask if you or any of your relatives are from Pakistan to get a taste.
Edit: ooh, downvotes away. Hah! No better way to tell when you hit a nerve than the torches come out.
This is the most common form of racism I've personally seen in my life, for what it's worth.
The funny part is having both Indians & Pakistanis pull you aside and tell you to watch out for the other ones because "They don't shower every day." I've had that happen a few times now...
And if you think Casteism is a bitch, Pakistani/Indian (or Indian Hindu vs Indian Muslim) is a bitch and a half. Just try to apply for a visa for India and see how many times they ask if you or any of your relatives are from Pakistan to get a taste.
Edit: ooh, downvotes away. Hah! No better way to tell when you hit a nerve than the torches come out.