You can also 68 something if it becomes available again, like a reverse 86. For instance: the kitchen runs out of Brussels sprouts and 86's them, but someone completes an emergency produce run to the local market and preps enough for the rest of the night, so now they're 68.

Interestingly enough, you can also 86 a person. This means they’re not allowed to come back to the bar/restaurant/etc…

Sounds like a murder/assassination euphemism.