These are modules, generally 5000 and 6000 level modules, or even 4000 level modules taken during NUS B.Eng. candidature, declared not to be computed as requirements for B.Eng. degree but for a subsequent NUS Engineering graduate degree (can be either for a M.Sc. coursework or research programme (i.e. M.Eng. or PhD)).
In other words, the NUS B.Eng student takes a module during his B.Eng. prior to gaining admission to a NUS Engineering Graduate Programme. The student needs to ascertain that the pre-taken module is relevant to the specific graduate engineering degree(s) for which he intends to gain admission to. In addition, he has to ensure that he is able to meet the admission requirements of the programme of study subsequently.