This is what my professor and TA told me yesterday in class. It turns out that field books used in surveying automatically become legal documents, even the ones we use in class. Because of their legal status, erasing is a big no-no. If we make a mistake we have to cross it out (while still making it possible to read what has been crossed out) and re-write it.
This is a huge problem for me because I'm kind of a perfectionist when it comes to having things neat and tidy. I caught myself erasing stray pencil marks. I erased and re-wrote some numbers to make them more centered in the graph. My tally marks were a little crooked so I erased and did those again, too. My TA said that he'll take off one point for every eraser mark he sees.
I hope I don't fail because of this.