Other countries have different gold standards. The U.S. for example has a minimum standard of 14ct, whereas Germany has 8ct. As 9ct gold is worth approximately 30 times as much as the same weight of silver, it is important to be assured of the standard, or indeed that the item is gold at all, and not just plated.
The UK has one of the best hallmarking systems in the world as each item is strictly tested and rejected if not up to standard. There are high penalties for forging the hallmark, which is stamped into the gold, and consists of the standard mark, a date letter for each year of manufacture ( the typeface changes when the end of the alphabet is reached, and is different for the different Assay Offices ) a number indicating the standard, and a unique maker's mark. It is necessary to register the mark with the Assay Office - if the initials are the same as another jeweller, another border must be chosen so that not only the date of manufacture, but also the jeweller that made the item can be identified.
The Byezantium hallmark is as registered with the London Assay Office more than 25 years ago. Below are some examples of Byezantium gold jewellery.