Diamond Marks for Registered Design
Some metal Whist Markers from this period have such a diamond mark as shown below (31st of January 1860).
![](web_images/diamond-mark-front.jpg)
![](web_images/diamond-mark-back.jpg)
The diamon mark carry several pieces of information (class of object, date of registration and bundle) as shown on the diagram below.
![](web_images/diamond-mark-explanation.gif)
![](web_images/diamond-mark-class-month-codes.jpg)
![](web_images/diamond-mark-year-codes.jpg)
For more details about diamond marks please visit the British National Archives.