After searching further, I found that there are many currency use same symbol.
(for example: USD$, TWD$, CNY￥, JPY￥)

and if we use the unique symbol i create, then we will need more procedure to type it out.
it will need new font or to be included in unicode, it is too far for us.
maybe someday it will be used for something.

So, if there are so many currency use the same symbol. why not we just use the same one $?
now i prefer SHA$, it is easy to use and remember. and will not to be confused.



of course, if you have any idea of this, you can suggest it here. thanks.