Which requirement must be met when marking an article with its country of origin?

The requirement for marking an article with its country of origin is that it must be permanent, legible, and conspicuous. This ensures that the country of origin is easily identifiable by consumers and authorities, which is crucial for transparency and compliance with regulations regarding imported goods. A permanent mark prevents smudging or wearing away, allowing the information to remain visible for the product's life. Legibility ensures that the marking can be read without difficulty, and conspicuous placement means that it should be easily found by anyone inspecting the product. This standard helps maintain fair trade practices and informs consumers about where goods are produced, playing an important role in international commerce and trade law.

Other options, while they may suggest methods of marking, do not encompass the essential legal requirements regarding visibility, permanence, and clarity of the origin marking.