Japanese GD&T standard?

[COLOR=#333333][FONT=Arial]I have Japanese drawings and when i see it i did not understood it. Center of hole is shown as A1, B1 and C1 as if it is datum point. Similar Datum target point symbol can be seen on other places as well like C2, B2, A3 and so on. My ASME logic is also not helping me to understand it. Do Japanese follow some kind of GD&T standard which i am not aware of?[/FONT][/COLOR]

What standard is stated on the engineering drawing?

Without seeing the drawing or specification I can't be 100% sure, however the Japanese do use a derivative of ISO 1101 G&T standard.

My guess is that this is an implied datum origin or an extension of datum target location definitions.

Can you post the relevant details of the drawing?