That is when a business like a distributor calls and orders something specific just for them. It isn't released like everything else and mass produced in a full production run. It is just a small run usually for someone specific who paid and ordered it from the manufacture. Most companies do this.
Hammer did it recently with the Hi-Rev from a few months ago, the Track Project was another. Bowlingball.com did some through Brunswick where they re-released some Quantum and other retro Brunswick equipment.
"Get out of bowling what you want because that is all there is."