Product classification standards like eCl@ss and UNSPSC define tens of thousands of product categories, and some standards additionally provide specific product property definitions and enumerated values. Many organizations hold respective meta-data for their products readily available in back-end databases. While many approaches have been presented for using such standards for more granular product information on the Web of Data, none has so far received mainstream adoption. This can be partly explained by legal, technical, and administrative barriers for adoption. In this paper, we describe a novel approach for using product classification standards in Web data markup in Microdata and JSON-LD syntax that does not require the availability of proper Web ontology variants of the underlying standards. We can show that the approach can provide the very same effect for the consumption and interpretation of the resulting mark-up in a Linked Data and Semantic Web context. Our proposal has already been integrated into the official version of schema.org and can be readily used for research and business applications.