First NSI domain invoice burning. This was for "dnso.com" which held a canonical list of organizational acronyms such as "IAHC". It expired and eventually fell off the net. A month later I got a call from network solutions. They needed to look up one of the acronyms and could I put the domain back so they could read it.
I live for this kind of irony and explained of all the people in the world they were best qualified and able to put the domain back into the working pile and they they cold read it. They said they cold not do that.
So I suggested they put a styrofoam coffee cup on top of the fridge in the coffee room asking for donations.
The domain worked within the hour.