Given the availability and ample choice of methods, processes, tools and environments for sharing knowledge on the web 20 years of research has yielded a vast body of literature it is surprising that the adoption of knowledge sharing artefacts designed to optimise knowledge exchange on the web is still limited. In related work, a systematic review of publicly funded systems engineering (SE) research in the United Kingdom is undertaken, the outcomes of which contribute to motivating the ongoing search for simple standardised shared knowledge representations and formalisation mechanisms. This paper defines knowledge objects (KOs) as identified in the literature, and explores their role as a possible codification method for facilitating and reducing the costs associated with knowledge sharing of system knowledge. The paper suggests that KO architectures should aim to integrate various knowledge types, and provides two KO outlines, system knowledge object (SKO) and systems engineering knowledge object (SEKO), together with suggestions for future work. Knowledge Management Research & Practice (2013) 11, 23-31. doi: 10.1057/kmrp.2012.45; published online 29 October 2012