Sometimes questions get closed as a duplicate, when it might not be.

A comment should be left for the user explaining how to get their question re-opened if the duplicate doesn't solve their problem (also asking for the reason why it doesn't solve the problem).

So now, how does one flag their question for re-opening?

Sometimes questions get closed as a duplicate, when they might not be one.

A comment should be left by the close-voter for the user explaining how to get their question re-opened if the duplicate doesn't solve their problem (also asking for the reason why it doesn't solve the problem).

So now, how does one flag their question for re-opening?