IPC is an enumeration classification used for patent literature classification, and also translated into international patent classification table. IPC classifies all technical contents related to invention patents step by step according to departments, divisions, categories, subcategories, main groups and groups, forming a complete hierarchical classification system. The whole table is divided into 8 series and 20 families and published in 9 volumes. Volume 1 ~ 8 is a detailed classification table, and volume 9 is a user guide and a brief classification table (up to the main group level).
The part of the symbol IPC (the first category) is represented by a ~ H, and the division is just a category title, so it is not marked. The category number consists of the category number of the department plus 2 digits. The minor category number consists of department number, major category number and capital letters. The main group number consists of the small class number plus 2 digits. The grouping class number consists of a diagonal followed by 2-5 digits.
For example, "A43D95/ 16 Polishing Tools for Shoe Making" (grouped) belongs to the department of necessities (department number A), the category of footwear (category number A43), the category of machinery, tools, equipment and methods (category number A43D) and the category of finishing machinery for footwear.