• 1 Vrije Universiteit Amsterdam
• 2 University of Bern
• 3 Huygens Institute for History and Culture of the Netherlands
• 4 Tilburg University
• 5 Royal Netherlands Academy of Arts and Sciences
• 6 Université de Montréal
• 7 NIOD Institute for War, Holocaust and Genocide Studies
• 8 VUC Aarhus
• 9 READ-COOP SCE, Austria
• 10 American Historical Association
• 11 University of Edinburgh
• 12 Amsterdam city Archives

This paper discusses best practices for sharing and reusing Ground Truth in Handwritten Text Recognition infrastructures, as well as ways to reference and acknowledge contributions to the creation and enrichment of data within these systems. We discuss how one can place Ground Truth data in a repository and, subsequently, inform others through HTR-United. Furthermore, we want to suggest appropriate citation methods for ATR data, models, and contributions made by volunteers. Moreover, when using digitised sources (digital facsimiles), it becomes increasingly important to distinguish between the physical object and the digital collection. These topics all relate to the proper acknowledgement of labour put into digitising, transcribing, and sharing Ground Truth HTR data. This also points to broader issues surrounding the use of machine learning in archival and library contexts, and how the community should begin to acknowledge and record both contributions and data provenance.