Like i said before I like the phone line, but if i wanted to get rid of it i would use a black sharpie on the base side of the negative. Sharpie ink sticks well to the base side (no extra tooth needed) and you can remove it if you make a mistake. Use a really pointy sharpie. You will then have to spot the print.
Some people use retouching ink on the emulsion side, but i find the base side a little safer.
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