The aims of this article are threefold: first, to revise some key concepts on the theory of scholarly digital editions such as scale and interactivity; second, to present the principles of XML/TEI encoding model and highlight the representation of the critical apparatus; third, to describe the methodology implemented to encode scribal and authorial variants of Luis de Góngora’s Soledades found in 22 witnesses. In general terms, it is argued here that TEI elements such as , and should be allowed to nest structural elements, in order to represent textual variation with accuracy.