A more thorough explanation:

The Assignment Division is a department within the U.S. Patent and Trademark Office that is responsible for keeping track of ownership changes for patents and trademarks. This means that they record any documents that affect who owns a patent or trademark application, registration, or patent.

For example, if a company sells a patent to another company, they would need to file a document with the Assignment Division to transfer ownership. The Assignment Division would then update their records to reflect the new owner.

Another example would be if an inventor wants to add a co-inventor to their patent application. They would need to file a document with the Assignment Division to add the co-inventor's name to the application.

The Assignment Division plays an important role in ensuring that the correct parties are listed as owners of patents and trademarks. This helps to prevent disputes over ownership and allows for proper licensing and enforcement of intellectual property rights.