Play by Their Rule

Which form are you going to use?
In the instructions of that form or any IRS publication, where did it say a married person could file as single?

(I really don't know the answers to the above questions. If you know, please post here.)

For the filing status: married file separately, where did it say that it require spouse's itin/ssn?

The interesting thing here is that for a married person, you may choose the only impossible choice: single. ^_^