Unlike in the United Kingdom or other countries, being listed on the National Register comes with no inherent federal mandate for preservation, either on the part of the owner of the property or by local, state, or the federal government. Yet it is hard to underestimate the scope of the National Register’s true impact. Listing in the National Register (or eligibility for listing) is a commonly used threshold for qualification to participate in a wide variety of both governmental and non-governmental programs. The National Register criteria provide a guide to eligibility for consideration by federal agencies planning projects that may impact historic properties, a process known as “Section 106 compliance.” Eligibility for listing is the standard for participation in the federal rehabilitation tax credit program as well as for many state level rehabilitation tax credit programs that support the appropriate rehabilitation of historic properties. The National Register criteria are often adopted by the state and local governments to guide protective measures established through zoning or easement programs.