I have five of these notes, two are AA00000000 serial format and three are A0A0000000 serial format.
One of the AA00000000 serial format notes, with a prefix of SG has UV activity on the reverse:
I had a look at this carefully in the dark and it looks like it is fluorescence to me.
Has anyone else seen this on any of these 1980s 5 Jiao notes?