It has been argued that it is in the best interests of IT professionals, to adopt and enforce professional codes in the work place. Yet applying the Australian Computer Society's Code of Ethics in actual every day situations has been left to individuals. This paper aims to help usability engineers interpret the code. This is achieved by utilising five case studies both directly in terms of the ethical issues involved and in the light of the code. The paper also examines the short-comings of the code in the domain of usability engineering. The paper concludes with suggestions of how the code might be enhanced to better aid the HCI professional in their work.