Have you ever ask a question why the 3rd Series of RM1 blind spot deviated from the traditional "dot", but instead a diamond sharp was introduced? Do you give yourself a second thought on this matter?
3rd Series of RM1 with a diamond sharp of blind spot
To trace back the history, the 3rd Series of Malaysian Banknote was introduced back in 1996 with the theme of Wawasan 2020. The introduction of this new series was began with lowest denomination of RM2 instead of RM1 compared to its previous two series. A traditional single "dot" was assigned to this RM2, the lowest denomination of the initial 3rd Series. It was only four years later or in 2000, the RM1 paper note was reintroduced. By then, the RM1 has not choice but to carry a different blind mark i.e. diamond sharp.
In deed, it was intention of Bank Negara Malaysia (BNM) back then to face off the RM1 paper note and to replace it with RM1 coin which was introduced in 1989, known as gold coin. However, due to the technical problem of standardisation of two different versions of minted coins and forgery issue, the RM1 coin was finally withdrawn from the circulation and demonetised in 2005.
I think the general public are happy with the BNM decision by re-introducing the RM1 paper note mainly because the RM1 coin is simply to heavy and troublesome to carry.
The single "dot" blind spot was used in RM2