Which of the following is NOT a type of rabbit fur?

Silky is not recognized as a standard type of rabbit fur in the classifications commonly used within rabbit breeding and showing. The term "silky" may refer to a texture or appearance but does not correspond to an officially recognized fur type.

Normal, Satin, and Rex are well-defined fur types. Normal fur is thick and dense, characteristic of many common rabbit breeds. Satin fur has a unique sheen due to its structure, giving it a glossy appearance, which is a desirable trait in show rabbits. Rex fur is known for its soft, velvety feel and is shorter than normal fur, making it quite distinctive. Therefore, recognizing "Silky" as not being an official type helps reinforce the understanding of rabbit fur classifications.