Understanding Overlapping Markup in Digital Humanities and Document Analysis

In markup languages and the digital humanities, overlap occurs when a document has two or more structures that interact in a non-hierarchical manner.

A document with overlapping markup cannot be represented as a tree.

This is also known as concurrent markup.

Overlap happens, for instance, in poetry, where there may be a metrical structure of feet and lines; a linguistic structure of sentences and quotations; and a physical structure of volumes and pages and editorial annotations.

The structural differences between multiple editions of Frankenstein have been analysed with overlapping