A patent application is filed on:

Form 2 is a request for continued examination. This form is used to request that the USPTO continue examination of a patent application that has been abandoned.

Form 3 is a request for reconsideration. This form is used to request that the USPTO reconsider a decision that has been made in a patent application.

Form 4 is a request for reexamination. This form is used to request that the USPTO reexamine a patent that has been issued.

I hope this helps!