Example of a fairly 'standard' script / screenplay formatted file (with indented left margin),
exported from a Final Draft document:

In this sample, the Left Margin is at column 16 (15 SPACES indented -- Scene Headings and Action),
the Character Names are at column 36, the Dialogue is at column 26, Parentheticals are at column 30,
and Transitions are at Column 56. (these informational lines are NOT indented, so are at Column 1)

00000000011111111112222222222333333333344444444445555555555666666666677777777778 (Ruler Tens)
12345678901234567890123456789012345678901234567890123456789012345678901234567890 (Ruler Ones)

               EXT. - HOUSE - DAY  [--Scene Heading]

                                                       FADE IN:  [--Transition]

               LONG SHOT [--Shot direction; generally only used for 'Shooting Scripts']

               [--Action] Vehicle drives up drive way and stops. GUY (button-down
               shirt, tucked in, blue jeans) gets out of vehicle (puts
               something in the back of his waistband / belt (handgun) that
               is not evident) and walks toward front door of house. Cell
               phone in his pocket rings. (distinctive ring) He takes out
               phone and answers it.

                                   GUY
                             (glibly)
                         Y'ellow.

               ...short pause as he's listening and walking, toward
               camera...

                                   GUY (CONT'D)
                         Hey, what's up?

                                                       CUT TO:

               MED LONG SHOT

               Guy walking away from camera. You see a handgun shoved in his
               pants at back. He reaches the front door and unlocks it.

                                   GUY (CONT'D)
                         I just got home. I'm walking in the
                         front door as I speak.

               Guy enters door and closes it.

                                                       CROSS CUT TO:

               INT. - HOUSE - DAY