There is no uniform standard. White plates must be used for the main tableware. There can be no pattern. Mainly circular flat plate. Now someone uses a square flat plate.

In addition, the main course is generally 12 inch white flat plate.

Salads and appetizers are not required, usually 12 inch or 18 inch salad plate or white flat plate.

Soup. I used to use ear soup cups, but now I use flat soup plates!

Western restaurants in our hotel generally follow this standard.