Question about the characters on Japanese Yen banknotes


Apologies in advance if this is not the best place for this question.
Apologies also that I couldn't "tag" this question very well as I had to fight
with the tagging system for 5 minutes before I could post this question with a
tag that was not completely irrelevant :( If anyone is familiar with
currency/banknote tracking, e.g. Where's George or EuroBillTracker, I am
currently working to build one, I'm working on one of my own, for the Japanese
Yen. Eventually I will make a "generic" version and post that free on GitHub
so that anyone with PHP knowledge can make one for their own country/currency
(instead of it being like currency tracking where every tracker organisation
has to write their own tracker project code from scratch), but that's a long
way off yet.

My question is about a symbol I've seen in some images of Yen banknotes, with
particular reference to the serial number (which is key for bill tracking). If
you look at this image from Wikipedia (although there are other examples of
notes with the same character) here:
<https://en.wikipedia.org/wiki/Banknotes_of_the_Japanese_yen#/media/File:1000_yen_Natsume_Soseki.jpg>

You see that the serial number of that bill is: ZP5494(something)4U

Where I wrote (something) in there, it is because I cannot understand what
that symbol is. As I understand it, the currency nominally has the Roman
alphabet and Indo-Arabic numerals, like Western currency, but this symbol
looks to me to be an exception of some kind. It looks like a cross between a 2
and 9, or a 9 with a tail on its bottom, or something, but I have no idea what
that is. Does anyone know what that might be or where I can find out?

Thanks in advance,

-Sean




If you mean [![this
picture](https://i.stack.imgur.com/yjwf5.png)](https://i.stack.imgur.com/yjwf5.png),
this is just an Arabic numeral `2`. This font has been used since 1964, but
current 10000 yen notes use a different font. This way of writing 2 is not
popular in Japan, either, and even native Japanese speakers [occasionally
wonder what this
is](https://detail.chiebukuro.yahoo.co.jp/qa/question_detail/q11108599286).
[This page](http://www.bekkoame.ne.jp/~muraoka/shihei_1.html) says this unique
font may be for preventing/detecting bill forgery.

By the way, if you're interested in tracking, note that the color of the
number is also important:

[![enter image description
here](https://i.stack.imgur.com/txD9a.png)](https://i.stack.imgur.com/txD9a.png)




If you mean [![this
picture](https://i.stack.imgur.com/yjwf5.png)](https://i.stack.imgur.com/yjwf5.png),
this is just an Arabic numeral `2`. This font has been used since 1964, but
current 10000 yen notes use a different font. This way of writing 2 is not
popular in Japan, either, and even native Japanese speakers [occasionally
wonder what this
is](https://detail.chiebukuro.yahoo.co.jp/qa/question_detail/q11108599286).
[This page](http://www.bekkoame.ne.jp/~muraoka/shihei_1.html) says this unique
font may be for preventing/detecting bill forgery.

By the way, if you're interested in tracking, note that the color of the
number is also important:

[![enter image description
here](https://i.stack.imgur.com/txD9a.png)](https://i.stack.imgur.com/txD9a.png)

