poorly marked broken black?
"Broken" means that the rabbit's fur has whatever color mixed with white fur. So, "broken black" means "black and white".
"Poorly marked" refers to how the black is distributed across the rabbit's body, and how much there is. Basically, the breed standard would define how much of the body can be colored (from looking at a few breeds, it seems like most of them expect at least 10% color, no more than 90% white). The colored patches should usually be entirely colored, not mixed with white.
Also, the breed standard would determine what the configuration of the colored patches should be - for example, some breeds require a "butterfly" marking on the nose. Others require a stripe down the back, or evenly distributed and symmetrical spots, or perhaps larger blotches but only behind the front legs, and so on.
For example, look at this broken black Mini-Rex rabbit - notice how much of the fur is black, and the "butterfly" on the nose:
If you look at
the RO key "patterned fur" pages, you can see some of the variations
Not being a breeder, and not knowing what breed your bunny is (if it is any particular breed), I can't say much more than that.
