A more thorough explanation:

Definition: Sui generis is a Latin expression that means "of its own kind." It refers to something that is unique and does not fit into any other category.

In legal contexts, sui generis is used to describe something that has its own independent legal classification. For example, a company may be considered sui generis if it does not fit into any existing legal categories.

Another example of sui generis is the platypus, a mammal that lays eggs and has a duck-like bill. The platypus is considered sui generis because it is so unique that it cannot be classified as a typical mammal or bird.

These examples illustrate how sui generis refers to something that is one-of-a-kind and cannot be easily categorized or classified.