TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

Description

Y10T serves as a mapping and transitional classification that bridges the former United States Patent Classification (USPC) system with the current CPC framework. It captures technical subject matter that was previously organized under USPC but does not map directly to standard IPC/CPC hierarchies, functioning as a cross-reference archive for historical patent documents and legacy classification data. This subclass is primarily used for indexing and retrieval purposes rather than for newly issued patents, enabling continuity in patent searching and prior art analysis across the transition from USPC to CPC systems. Y10T subdivisions correspond to specific USPC technical digest categories and art collections (XRACs), preserving the searchability of older patent literature classified under the discontinued American system.