For OCR, however, this is a major drawback. Most OCR-models are trained to work with one of three different training sets, based on either just modern antiqua-fonts or on 19th-century standard Fraktur or on all fonts that ever existed. Specialised OCR-models, e. g. for Rotunda or Textura, almost don’t exist as they would be very difficult to apply. One reason for this is that metadata for digitised books usually does not include the the font group or even the font of the main text face. Therefore, these models would - at the moment - only be applicable if the font is recognised manually. Given the vast amount of digital copies rendered by the large-scale digitisation projects like those for VD16, VD17 and VD18, this is out of the question.