How do you use jr in last names

English as a Second Language English Vocabulary, Grammar and Idioms
1

For instance: Richard E. Smith Jr.

Do you write?: Smith, E. Jr, Richard? Or this is wrong?

Thank you.

2

If his name was Richard E. Smith Jr. and you wanted last names first, you would write Smith, Richard E. Jr.

3

And when you fill out any form and it asks your last name first, do you write Smith without jr?

Thank you.