Project Urdar is a collaboration between Uppsala University and the Swedish National Heritage Board. It was initiated in 2020 with the aim of ensuring that thousands of georeferenced field documentation databases are transformed from proprietary formats into open and reusable ones. Preservation is only part of the goal, as the data also needs to be made accessible and interoperable, useful for further analysis and knowledge production. Dealing with legacy data which is still only 5-20 years old has brought the team a lot of insight into the challenges facing 21st C archaeology. The professionalisation and adoption of digital methods will paradoxically result in worse preservation of knowledge from excavations undertaken in the previous centuries, unless major changes are implemented. The challenges are only partly technical, mostly it is a question of human practice and incentive, from field archaeologists to government agencies. We present the ongoing work FAIRifying digitally born field documentation from Swedish contract archaeology, and the technical and human issues that have to be dealt with, as well as some uses that are possible. The data should still be considered as raw field documentation and needs to be complemented with information available in the reports. Attempting to reuse the data, and to recreate the interpretive process of the excavation serves to illustrate some of the challenges of reuse of documentation out of context.