Revenue Type or Coastal Type?

Some Cash coins are divided in Board of Revenue Type and Coastal Province Type?
I got here a Cash coin made during the Jiaqing (1796-1820). It is from the Kiangsu Province , Suzhou mint.
This type is divided in the 2 above mentioned types
How can you tell the difference?

Hello

it is most often a difference in the characters as well as the diameter of the coin
but without pictures and diameter it's quite hardto be able to give you an answer

This is the coin I am referring to

Diameter is 22,2 mm and weight is 3,35 gram

it's the Hartill 22.523 cause of the shape of the right caracter
If you want to exchange it please PM me

Do you mean the square head of T'ong?
Is the difference between coastal and revenue always this square vs hooked head?

Yes for this one but not sure it's Always like that and there is also a difference of the su

Thank you for helping me out