Which indication can be used in connection with a registered design?
There is (so far) no internationally recognized symbol for this category of rights. In Canada and other countries the letter D in a circle seems to have become the symbol for a registered design.

Possible references to a registered design in Switzerland are: "Registered Design".

For international filings (under the Hague Agreement), the indication "mod.int.dép." (international model filed) is appropriate.

In the United States and Great Britain, it is important to always mention the number of the design registration; it is usual to put the phrase "Registered UK Design No. ...." or "U.S. Design Pat. No. …." respectively.

As to Canada, the indication of the registration number is less important; instead it is recommended to always make a reference to the proprietor of the design registration, e.g. “ "D in circle" John Brown Inc.”.

Misuse or improper use of alleged design protection may have legal consequences. The indication that design protection exists has to be in full conformity with the facts. It is important to make a distinction between a pending design application and a registered design. At the same time it is essential to avoid misleading the public by using an indication concerning design protection in a country where no such protection exists.