9902.11.29 - Poly(1,4-benzenedicarboxylic acid-co-1,4-butanediol-co-nonanedioic acid) (CAS No. 26590-80-7) (provided for in subheading 3907.99.50)

This HTS code, 9902.11.29, covers a specific type of polyester, identified as Poly(1,4-benzenedicarboxylic acid-co-1,4-butanediol-co-nonanedioic acid) (CAS No. 26590-80-7). This classification is part of Chapter 99, which pertains to temporary legislation, temporary modifications under trade agreements, and additional import restrictions. The inclusion of "provided for in subheading 3907.99.50" indicates that this material is essentially a polymer falling under a broader polyester classification within Section VII (Plastics and articles thereof) of the HTS, but is subject to specific temporary provisions and potential restrictions outlined in Chapter 99.

As a leaf node within Chapter 99, 9902.11.29 does not have further subcategories. Its purpose is to designate a particular polymer that might be subject to quotas, temporary duties, or other specific regulations for import. This differs from the general import classifications found in Chapters 1 through 97, which are typically permanent and based on the inherent nature of the goods. While other products might be classified under broader polyester headings in Section VII, this specific code is for that polymer when imported under the stipulated temporary provisions of Chapter 99, implying it has a unique trade or policy consideration.