What should the indication that a patent has been applied for or has been granted look like?
Above all an important distinction must be made between a patent application and a granted patent.

In the United States where it is compulsory for the number of the granted patent to be given with the marking "pat." or "patented", only this type of marking brings legal advantages in case of litigation.

The marking "patent pending" or "patent applied for" has, in contrast, no legal advantage. These markings, as long as they are true, may on the other hand have a strong dissuasive impact. However if the patent finally is not granted these indications should be withdrawn immediately . Otherwise they would be misleading.
Use of the indications "pat.", "patented", "world patent" or "EP patent", etc., even though for the time being a patent application is still pending and not granted, can have penal consequences in most countries. Conversely, "pat. pend.", "patent pending", "patent application filed", etc. are likewise misleading markings if the patent has already been granted.

Normally patent applicants are informed some weeks or months in advance about the grant of the patent. This period of time should be used to adapt the indication accordingly in documentation, advertising materials and on the respective products.

The indication that a patent application is pending or a patent has been granted should be made in the national language and in accordance with the national legislation of the counrty where it will be used.