The in-laws just arrived at the airport and are going to be here any moment. Your running around making sure the house is spotless, everything is put away and organized, not a spec of dust to be seen! You look and you see a scratch on your floor from moving your coffee table, what do you do? There no time to use a Pre-finish filler and the in-laws will surely notice and criticize you for not taking care of your floors.
Grab a sharpie (black, brown or red are the most likely choices depending on the color of your floor) dab over the scratch then wipe off with your finger or a paper towel. By wiping the scratch after you color it in with the sharpie you will remove the excess color from the finish leaving the color only in the scratch. The scratch will hardly be noticeable as long as its not horribly deep until you have the time to fix the scratch with a proper pre-finish filler.