This document discusses open data in archaeology. It defines open data as content or data that anyone is free to use, reuse, and redistribute, subject to attribution and sharing-alike requirements. The document outlines momentum for open data from open government initiatives and advocates for open licensing of archaeological data to increase impact and encourage reuse. However, it notes challenges including episodic and unsustainable open data efforts, lack of long-term preservation, balancing openness with cultural sensitivities, and avoiding "non-commercial" licenses that do not have clear definitions. Overall, the document promotes individual and institutional advocacy for open archaeological data standards and best practices.