Abstract
The dataset contains TEI-compliant XML files based on the custom-made non-proprietary XML code developed for the DigitalSEE Project of the University of Sofia. The initial XML code is used by the project to describe geo-annotated historical and archaeological data derived from various sources (such as descriptions in historical documents, archaeological records, etc.). The data are stored in XML and JSON master formats and their visualization is provided by the DigitalSEE platform. However, the original data are not interoperable and further transformations are needed to ensure their compliance with the most widely recognized and applied TEI P5 standards. The present paper describes these transformations and the basic features of their output.