This document discusses the concept of dual levels of historical significance in digital data and the importance of preserving data with such dual significance. It addresses what historical significance means, how it can vary between local, regional, national and international communities, and how digitization can sometimes increase significance. It argues that data needs to be locatable, reusable, and machine-readable to have greater value when combined with other data, and that adding scholarly context and interpretation through metadata is important. The document closes by stating that unless data is discoverable and usable, there is little reason to make it openly available online, and that people create significance through applying data to knowledge and research.