The catalogue of documents is compiled in form of a CSV database. It offers information about the original materials' whereabouts, their accessibility online, their senders and receivers (including names and locations), the documents' dates, and it serves to identify the transcriptions that were produced of the documents and also included in this dataset. The transcriptions are provided in two formats: (1) formatted text using Markdown language in order to reproduce the the documents' original layout and (2) plaint text transcriptions.