I love knitters. They are constructive and creative and all are armed with sharp sticks. Long ago it seems they claimed the acronym UFO as the shortened reference to unfinished object, and all seem to object to my use of the same acronyn in reference to my room full of cones of Unidentified Fiber Origin.
Almost all the fiber I have acquired has come second hand, and quite a bit of it is a complete mystery. What and where and how much have paled in comparison to pretty or shiny or soft in my purchasing decisions, and some skeins and cones I embrace with no questions asked. I have enough that it requires an easy reference.
In an effort not to rile the pointy stick people, I propose the following option: FU (pronounced foo) fiber. Fiber Unidentified. Burning may give a clue, but it’s always FU to you.