Excerpt from John O. Honnold, Uniform Law for International Sales under the 1980 United Nations Convention, 3rd ed. (1999), page 541. Reproduced with permission of the publisher, Kluwer Law International, The Hague.
The language of this article seems clear. In any event, denunciation would be handled by a foreign ministry which should be familiar with this process. The Secretary-General as depositary can be expected to notify Contracting States of important acts such as a denunciation. See Vienna Treaty on Treaties (1969) Article 77(1)(e).