The Art III:2 and Art III:4 cover the prohibition of discrimination concerning similar imported and domestic products. The inadmissible discrimination exists if either the same products are treated dissimilarly or if goods beyond the product-related criteria are discriminately treated, so as to afford protection to domestic production. The textual concept of ‘like product’ in Article III:2 may suggest a similarly narrow reading of ‘like product’ in Article III:4, since both provisions form part of the same Article. Hence, the question arises of what is the relationship between ‘like products’ under Art III:2 and Article III:4.
In the EC- Asbestos case, the Appellate Body examined the relationship between these paragraphs and stated that Article III:2 constitutes part of the context of Article III:4. Nevertheless, as mentioned above the Appellate Body hold that Article III:1 had ‘particular contextual significance’ for the interpretation of Article III:4:
Accordingly, in interpreting the term ‘like products’ in Article III:4, we must turn, first, to the ‘general principle’ in Article III:1, rather than to the term ‘like products’ in Article III:2.
Then, it proceeded to distinguish the concept of ‘likeness’ in Japan — Alcoholic Beverages from that in EC — Asbestos and recognized the different respective structures of both paragraphs. Art III:2 contains two separate commitments: the first sentence lays down obligations in respect of ‘like products’ and the second relies on obligations concerning ‘directly competitive or substitutable’ products respectively. Conversely, Article III:4 does not distinguish between different standards of product relationships and contains only one obligation which applies exclusively to ‘like product’. As a result, the ‘general principle’ articulated in Article III:1 is expressed in Article III:4, not through two distinct obligations, as in the two sentences in Article III:2, but through a single obligation that applies solely to ‘like products’. The ‘accordion’ of ‘likeness’ stretches in a different way in Article III:4 and therefore ‘like product’ involved in this paragraph is not equivalent with the one from paragraph 2.
Furthermore, referring to the EEC – Animal Feed Proteins case, Appellate Body clearly rejected the narrow interpretation of ‘like products’ of Art III:2 with regard to Article III:4 GATT. Following this argumentation, it was stressed that the ‘likeness’ standard has ‘a relatively broad product scope’ for article III:4 of the GATT, although no broader than in article III:2, second sentence. However, there is no sharp distinction between the term ‘like products’ in Art III:4 and directly competitive or substitutable’ products in Article III:2, second sentence and both forms of regulation can often be used to achieve the same ends.
It is argued by the scholars and commentators that Appellate Body implicitly confirmed that the breath of ‘like products’ in Article III:4 should be essentially identical to the breadth of ‘directly competitive or substitutable products’ articulated in Article III:2 GATT. In particular, it is highly improbable that two products would be ‘directly competitive or substitutable’ in terms of Article III:2, second sentence, but not ‘like’ in terms of Article III:4 GATT; or vice versa.  In effect, the ‘likeness’ standard in Art III:4 should rely on the same market-based factors as they apply to the ‘directly competitive or substitutable products’ of Article III:2, second sentence.
 Horn H., Mavroidis P.C., Non-discrimination, the Interpretation of National Treatment in the GATT/WTO Case-law on Tax Discrimination, p. 41f
 Appellate Body Report, EC – Asbestos, para. 94.
 Appellate Body Report, EC – Asbestos, para. 96.
 Appellate Body Report, EC – Asbestos, paras. 94-96.
 Panel Report, EEC – Animal Feed Proteins, paras. 4.2 f.
 Appellate Body Report, EC – Asbestos, para. 99;
 Choi W.-M., ‘Like Products’ in International Trade Law: Towards a Consistent GATT/WTO Jurisprudence pp. 111–14;
 Diebold N. F., Non-Discrimination in International Trade in Services, ‘Likeness’ in WTO/GATS, p. 115.