In this paper we propose a novel approach to markup, called Extreme Annotational RDF Markup (EARMARK), using RDF and OWL to annotate features in text content that cannot be mapped with usual markup languages. EARMARK provides a unifying framework to handle tree-based XML features as well as more complex markup for non-XML scenarios such as overlapping elements, repeated and non-contiguous ranges and structured attributes. EARMARK includes and expands the principles of XML markup, RDFa inline annotations and existing approaches to overlapping markup such as LMNL and TexMecs. EARMARK documents can also be linearized into plain XML by choosing any of a number of strategies to express a tree-based subset of the annotations as an XML structure and fitting in the remaining annotations through a number of “tricks”, markup expedients for hierarchical linearization of non-hierarchical features. EARMARK provides a solid platform for providing vocabulary-independent declarative support to ad...