The ground for refusal of the customary designation not only plays a role in the registration procedure, but can also be asserted subsequently in special revocation proceedings. The fact that a trade mark only mutates into a customary designation after registration occurs time and again as a result of negligent trade mark management. Such a trade mark can no longer fulfil its main function, i.e. the function of origin^[1]. In such cases, the legislator therefore gives priority to the public interest in the free usability of the trade mark over the interests of the trade mark proprietor and does not rely solely on the protectability at the time of registration, but allows for subsequent cancellation.
This makes it possible, for example, for a word such as ‘heroin’ - originally a pharmaceutical trade mark, later a generic name - to be cancelled.
Pursuant to Art. 58 I lit. b EUTMR, Section 49 II No. 2 MarkenG, a trade mark is therefore cancelled on request due to revocation if the trade mark has become the common name in the course of trade for a product or service for which it is registered as a result of the conduct or inactivity of its proprietor. Revocation proceedings have special features compared to cancellation proceedings due to absolute grounds for refusal. In particular, the legislator accommodates the interests of the trade mark proprietor insofar as the development of the customary designation must be based on the trade mark proprietor's behaviour or inactivity. This inactivity includes all omissions by which the proprietor of a trade mark does not show sufficient vigilance with regard to the preservation of the distinctive character of his trade mark.^[2] However, the trade mark proprietor is not liable for uses against which he has resisted.^[3]
This ‘inactivity’ may consist, for example, of the trade mark proprietor failing to prohibit third parties from using a sign that could be confused in good time before the trade mark is diluted.^[4] In addition, the condition is fulfilled if a trade mark proprietor does not urge its intermediaries to inform customers that the term in question is a trade mark and that the public therefore uses the trade mark as a generic term.