The system makes a distinction between four different forms of annotation: page (scan) descriptors, typically page titles, page regions of interest (tags for visual objects), transcription of segmented lines, and finally, word labeling. The system could export in TEI, however, within the OCR community, there is a preference for layout-centric description languages, as opposed to editorial descriptions. In practice, both TEI and PAGE are used, as well as other formalisms that allow to provide metadata to polygonal image sections.