Originally the information was distributed as a paper form, on yellow paper. Students enrolled face-to-face with a CSE staff member, and were required to sign a tear-off slip at the bottom of the yellow form, to acknowledge that they had received the information (e.g. the dates of the supplementary exams).
Nowadays, you are shown the yellow form electronically when you are assigned your CSE computing account, and you electronically acknowledge receipt of the information.
If you haven't written the supp dates in your diary for both semesters, please do so now. If you need to sit the supplementary examination, whether because of illness or another reason, you must be in Sydney on the relevant date.