What is the IPC hierarchical structure?
(see also paragraphs 19 to 23 of the Guide to the IPC) The Classification consists of several hierarchical levels: Sections – 1 st level Classes – 2 nd level Subclasses – 3 rd level Main groups – 4 th level Subgroups – 5 th and lower levels Subgroups may have different hierarchical levels; their hierarchical level is indicated by a certain number of dots, with a lower level corresponding to a higher number of dots. While the advanced level of the reformed IPC comprises all hierarchical levels, the core level comprises, with some exceptions, only the levels down to the highest subgroup levels.
