blark n. That which doesn't seem desirable, useful or true, but might to another; an object of subjective annoyance.
The rule of thumb is whether it could pass as a gift to someone else, within imagination.
His writing desk was overrun with an almost seamy mass of blark: old catalogs, unused coffee mugs, you name it.
A book on livestock shearing would just be more blark on the shelf!
This was coined mid-2000's for a perceived need in my vocabulary, and so far, no one's been confused by it.