The Japanese Occupation coins are not in the same currency category

For some reason, this 1 Sen coin is not put with the 5 Sen and the 10 Sen of the same period, despite that the 3 coins clearly are the same currency.
When I tried to add data, the “Occupation Gulden” of 1942-1944 is not listed as a currency option.

Unusual situation!

all three coins are affected. Trying to edit 5 or 10 sen pages results them flipping to unknown denomination. You should have posted your message on https://en.numista.com/forum/forum14.html forum and registered as ticket for admins to investigate it. Somebody deleted occupation gulden currency or unlinked it from Dutch East Indies.

I can't even remember authorising the move from Japan to the East Indies. Non of these coins ever circulated or even arrived there in large amounts and I think my position never changed in that regard. But I have no access to the change history to check if I'm wrong.

Yep. somebody manually changed country and managed to do that without updating currency/denomination details. Gulden (1942-1944) currency is coming from Japan.

What a complicated situation!
I thought it looked odd.

I think as per the other thread, it makes sense to not list them as “standard circulation coins”. But then again, on the “Japan” page, there were many coins that were melted down in their entirety and thus never circulated, but still listed as “standard circulation coins”.

I do prefer things to be standardised, but I appreciate that this is a complicated topic.

Idolenz

I can't even remember authorising the move from Japan to the East Indies. Non of these coins ever circulated or even arrived there in large amounts and I think my position never changed in that regard. But I have no access to the change history to check if I'm wrong.

I am trying to figure out what is going on from a catalog history viewpoint, and what the correct approach should be.

First, the 1 Sen and 10 Sen coins were entered into the catalog a long time ago (2011), and appear to have always had NEI as issuer as far as I can tell.

The 5 Sen coin was entered in 2015 with Japan as issuer.  It looks like the issuer was changed to NEI earlier this year, probably to be consistent. 

Additionally, it looks like the coins were attached to a currency Gulden 1942-44 during a big overhaul of the Numista currency/denomination system in 2024.  But I believe this is incorrect for these coins.  Although there were guilder denominated banknotes during the Japanese occupation, if these coins say “Sen” on them, I don't think they can be in a Gulden currency system.  

@Idolenz  I think if these were produced for use in NEI, then it is appropriate for them to remain there, even if they never circulated.  I'll also ask for @Jarcek  to comment in case there is a better approach.        

My proposal would be:

- create a Yen currency for NEI for 1942-44 to cover use of these (Japanese) denominations, and attach them correctly.

- categorize them as non-circulating.  If many millions were produced, they can't be patterns.

It appears that “Sen” is the word for “Cent” in several Asian languages, so perhaps it's a different name for the same denomination.
And I also think that anything produced in such quantity is not a pattern

That makes sense … so probably in the same currency system as the banknotes, meaning all we need to do is attach the denomination that's causing the problems.