white & black 'tea bowl'

Hello again. This little tea bowl sits on my shelf looking very pretty, has a beautiful clear mark, but yet it still remains a mystery pot.





It stands only 7cm tall, rim diameter 9.5cm. White body, thick white glaze inside & out with a continuous black decoration that looks and feels like it's been scratched into the white surface through to the black. The mark looks like either an A, D or possibly P with a dot. Any suggestions greatly appreciated, thanks.