Singapore $2, $5, (1999), President Ishak, BCCS, sign. Hu Tsu Tau, both with special prefix '0YI', and identical serial nos. 019441, graded PMG Gem UNC66EPQ and Superb Gem UNC67EPQ respectively. The $2 is incorrectly labelled by PMG as "S/N 0YI 019341". (2)