The term “proprietary rights” is used in several different ways in the legal community. All senses of the term relate to the idea of rights which go with ownership. Such rights are sometimes assumed, and sometimes structured into a contract so that all parties are clear on the specifics. Essentially, they are rights which the owners of something are allowed to exercise by nature of their ownership of the object, idea, process, property, or other item.
Proprietary rights to a business are all of the rights which go with business ownership, including the right to protect the name of the business and the brand. Likewise, people can have proprietary rights to real estate which they own, whether it is vacant, occupied by a home, or being used for another purpose. If these rights are violated, it can be grounds for a legal case as it would be considered infringement on the rights of the owner.
Likewise, people can hold and control the rights to proprietary information. This type of information is confidential by nature of being related to a proprietary process, containing personal details, and so forth. People with proprietary rights over things like intellectual property get to determine how, when, and where it can be used. Multiple people can hold shares, as seen when an author and publisher share proprietary rights to a book, or when a collective of engineers files a patent together.
These proprietary rights include the right to control how the information, concept, or equipment is used by a contractor. When a contractor is hired to complete some aspect of a project, the people with proprietary rights can spell out the terms of the contract to ensure that their rights are not violated. For example, a contractor might be hired to repair machinery with the understanding that the contractor will not photograph, sketch, or otherwise document the machinery, as this could violate the rights of its owners.
In this case, people may be asked to sign confidentiality disclosures which indicate that they understand that the information they are working on is proprietary, and that they will not infringe upon the rights of the owners. Violation of such agreement can expose someone to legal liability, and some companies protect their proprietary rights extremely aggressively in the interests of maintaining control of a process. Likewise, people who want to do things like using the name of a business in a promotion would need to get agreement from the rightsholder before doing so.
