The main aim of this study is to introduce a model of TEI (Text Encoding Initiative) annotation of Hebrew elements in Judaeo-Arabic texts, i.e. code-switching, borrowing and Hebrew quotations. This paper will provide an introduction to using XML (Extensible Markup Language) to investigate sociolinguistic aspects in medieval Judaeo-Arabic texts. Accordingly, it will suggest to what extent using XML is useful for investigating linguistic and sociolinguistic features in the Judaeo-Arabic paradigm. To provide an example for how XML annotation could be applied to Judaeo-Arabic texts, a corpus of 300 pages selected from three Judaeo-Arabic books has been manually annotated using the TEI P5. The annotation covers all instances of code-switching, borrowing, and Hebrew quotations in that corpus.