I want my last name spelled correctly
What is wrong with the way they are spelling your name?
I think it is proper that they learn as a sign of respect.
It is reasonable you want your name spelled correctly. It might help to tell others how to spell it when they do not know.
I don't think it is necessary, it's just one letter.
It is necessary, it is your name. It is only right that you want your name spelled correctly. You shouldn't back down on that or feel bad that you want it done correctly.