The image displays the underside of an antique Royal Worcester plate, featuring a manufacturer's mark. 

• Manufacturer: Royal Worcester, a renowned English porcelain company.

• Item: A vintage or antique plate, possibly from the late 19th century. 

• Markings: The blue diamond-shaped mark is a British Ceramic Registry mark, indicating the design was registered, with 16 indicating the day and other letters indicating the month and year of registratio

This item is a vintage ceramic plate featuring the backstamp mark for J.D. & Co. The mark identifies a pattern or manufacturer, possibly associated with Japanese-inspired designs popular during the late 19th-century Aesthetic Movement in England.

• Manufacturer/Mark: J.D. & Co.

• Style: Japonisme or Aesthetic Movement influence.

• Material: Earthenware or ironstone