When I had my first job as a receptionist, our fax still printed on thermal paper rolls and we had a particularly bright customer fax us a 50 page contract. I was almost in tears as I watched a newly replaced very expensive roll getting wasted in minutes. I called my supervisor to vent and he walked to my desk with a sharpie, wrote IMCOMPLETE across the roll and said “fax it back to them”. They were calling us back in less than a minute screeching on the phone to stop transmission.