4.2.1.1.6 Indexing Codes

Also in this Chapter:

• 4.2.1.1.1 Structure of the IPC
• 4.2.1.1.2 Headings and Titles
• 4.2.1.1.3 Definitions, Warnings and Notes
• 4.2.1.1.4 Function-Oriented and Application-Oriented Places
• 4.2.1.1.5 References​​​​​​​

Indexing codes have a format similar to classification symbols. Within subclasses having classification schemes, indexing schemes are placed after the classification scheme and their numbering starts with the number 101/00. Some subclasses are used only for indexing purposes, in association with classification symbols from one or more classification subclasses - this is indicated in their titles. Indexing subclasses usually employ the same numbering system used in the indexing schemes of classification subclasses (see subclasses F21W and F21Y), but sometimes their numbering systems may include numbers (for example, 1/00) similar to those normally associated with standard classification symbols (see subclasses C10N, C12R, B29K, B29L).

Indexing codes can only be applied in association with classification symbols. Each place in the Classification where indexing codes may be used is indicated by a note. Similarly, a note, title or heading before each indexing scheme indicates with which classification symbols those indexing codes are associated.

Whenever possible, the layout of the indexing schemes is hierarchical, facilitating their presentation. The numbering of some of the schemes is such that truncation of the indexing codes is feasible when carrying out database searching.

Example (part of the indexing scheme in subclass C04B):