Some information can be provided via questionnaires submitted to a supplier and answered by their Quality Assurance (QA) personnel. In fact, this is often a good way to begin to ensure basic requirements can be met. Additional information is typically shared during an on-site visit or audit of the facility. Even then, there may be proprietary information that a supplier does not wish to provide. In this is the case, a Drug Master Files (DMF) can be submitted by the supplier to regulatory authorities in the market of interest. This document contains extensive detail about the manufacturing process, including proprietary information. This allows the supplier to protect their intellectual property, while providing a mechanism for regulatory authorities to access the information, and for a customer to reference the DMF in a regulatory submission in the market of interest.