On manuscripts of Alexander von Humboldt sometimes so-called "Siglen" (tokens) can be found, i.e. combinations of 1-2 characters (e.g. "Ad") that relate different documents, letters and diary entries to each other. These token were not only transcribed, but also entered into a separate TEI-XML register and linked to it from the text passages. In this way, the relationships can also be traced in the digital edition.