with more than 270,000 members. You can visit their homepage for more information at: http://www.preservationnation.org . What are the definitions of some of the terms and acronyms you use? Bulletin 16A "How to Complete the National Register Registration Form" includes a glossary of terms that the National Register of Historic Places uses to evaluate historic properties. What is the difference between a National Park, a National Monument, a National Memorial, a National Historical Park, etc? The numerous designations within the National Park System sometime confuse visitors.The NPS has a page that defines the many different designations that exist.