Stains starting with N
Nail polish
Nail polish dissolves in acetone, or thinner (never remove nail polish stains with nail polish remover), but the use of acetone creates risks, especially on acrylic.
Nicotine
You can remove nicotine stains with lemon juice. Bleach also helps. You can also clean painted walls, mix soapy water with a splash of ammonia. Do the whole wall, otherwise you see color difference.
Night cream
You can treat this as a grease stain, let the detergent on for a while and then wash.