The existing MathML 3 working draft proposes major changes to the content MathML markup elements. The proposed changes address a significant omission in the representation and communication of mathematical information. However, the current form for the proposed changes appears to abandon the needs of a significant community of mathematical users and applications, that is, those users for whom structural (content) information is paramount, but who have no requirement for the semantic (deductive) information that has historically been the domain of the OpenMath standards.

This paper proposes an alternate reformulation of the MathML~2 content markup elements. The purpose for this reformulation is to refocus the design of the content elements on the functional expression tree structure of a mathematical expression. Along the way, this paper identifies several opportunities to increase the extensibility of the content MathML markup elements to vocabularies of custom content operators, and to increase the level of interoperability of content MathML with OpenMath semantic markup.