
The modules in this directory are part of the schema that defines 
a vocabulary and grammar for EPUB3 XHTML Content Documents [1], 
based on W3C HTML [2], with EPUB extensions. 

The modules are derived from the schemas used in the Nu Html Checker [3]. 

[1] p://www.idpf.org/epub3/latest/contentdocs
[2] https://www.w3.org/TR/html/
[3] https://validator.github.io/validator/ 
