TEI (Text Encoding Initiative), now collectively defines a standard XML format for the scholarly representation of all kinds of texts in digital form. It also provides solutions for enriching the transcribed text with information on the material and structural features of the sources, as well as for instance on performative, genetic, revision-historical, linguistic (phonetic, orthographic, lexical, syntactic), editorial and comparative layers of the text. The document as text can then be presented with metadata and explanatory features, as well as links to manuscript images […], different manuscript variants or even audio and visual material for more recently recorded examples.
(Katajamäki et al. 2013, 12-13)