One of the intellectual threads to which Suellen Shay contributed was describing the curriculum structure of professional and vocational education. This work was part of the Bernsteinian call for a return to knowledge in the curriculum. But education for vocations and professions, termed 'regions', remains a vexing problem. Turning to LCT (Semantics), Shay attempted to elevate the knowledge produced in practice to that of theoretical knowledge. Although laying the foundations she did not fully capture the complex "conceptual" nature of knowledge of the contextual detail central to practice. Using empirical data from an engineering curriculum, this paper develops an alternative conceptualisation of 'practical knowledge' in terms of knowledge of the contextual details of professional problems. Professions recruit theory to solve contextually emergent problems, suggesting knowledge of the material detail is the origin of reasoning, Symbolic relations do function to develop reasoning in professional problems, but material relations dictate which knowledge is relevant.