It seems that Singapore is up to their old tricks again with the money printed with the words KF on the top right hand corner and that have seem to hurt the confidence in the currency as local banks have not been careful enough to pass through these mutilated notes. To many mutilated notes carry no value, but to some, these are a gem to many philatelist and currency collectors as mutilated notes fetch high value.
Take a good example are replacement series notes, like the Z series in Singapore and Malaysia or the CB issue in the US where these are not yet in circulation, unless by virtue of a gazette or a batch of currency was defaced while in print, which was detected and exchanged with a replacement note.
I am an avid collector of currency and among those 'useless' currencies include the recalled RM1000 and RM10,000 (seribu ringgit and the sepuluh ribu ringgit) notes along with the RM500 note which have been declared no-value after the currency crisis to defray any currency being smuggled out in huge quantities.
Likewise, in Singapore, the ancient S$20 and the S$25 have disappeared from circulation other than an out of the blue commemorative issue, like the recent golden issue of the $25 and the $50. Likewise, Malaysia have wiped off the RM20 note from circulation totally.
One thing though, a RM1000 note in good condition fetch as much as US$4500 as the rarity of the currency is now as rare as a penny black stamp.Just like the S$25 Orchid series fetch as much as 10 times as much as the face value.
So, next time you think you have useless currency, it may be worth far off.