2013 International Patent Classification (IPC).

A SECTION A — HUMAN NECESSITIES.
B SECTION B — PERFORMING OPERATIONS; TRANSPORTING.
C SECTION C — CHEMISTRY; METALLURGY.
Notes[n] C:
  • In section C, the definitions of groups of chemical elements are as follows:
    • Alkali metals: Li, Na, K, Rb, Cs, Fr
    • Alkaline earth metals: Ca, Sr, Ba, Ra
    • Lanthanides: elements with atomic numbers 57 to 71 inclusive
    • Rare earths: Sc, Y, Lanthanides
    • Actinides: elements with atomic numbers 89 to 103 inclusive
    • Refractory metals: Ti, V, Cr, Zr, Nb, Mo, Hf, Ta, W
    • Halogens: F, Cl, Br, I, At
    • Noble gases: He, Ne, Ar, Kr, Xe, Rn
    • Platinum group: Os, Ir, Pt, Ru, Rh, Pd
    • Noble metals: Ag, Au, Platinum group
    • Light metals: alkali metals, alkaline earth metals, Be, Al, Mg
    • Heavy metals: metals other than light metals
    • Iron group: Fe, Co, Ni
    • Non-metals: H, B, C, Si, N, P, O, S, Se, Te, noble gases, halogens
    • Metals: elements other than non-metals
    • Transition elements: elements with atomic numbers 21 to 30 inclusive, 39 to 48 inclusive, 57 to 80 inclusive, 89 upwards
  • Section C covers :
    • pure chemistry, which covers inorganic compounds, organic compounds, macromolecular compounds, and their methods of preparation;
    • applied chemistry, which covers compositions containing the above compounds, such as: glass, ceramics, fertilisers, plastics compositions, paints, products of the petroleum industry. It also covers certain compositions on account of their having particular properties rendering them suitable for certain purposes, as in the case of explosives, dyestuffs, adhesives, lubricants, and detergents;
    • certain marginal industries, such as the manufacture of coke and of solid or gaseous fuels, the production and refining of oils, fats and waxes, the fermentation industry (e.g., brewing and wine-making), the sugar industry;
    • certain operations or treatments, which are either purely mechanical, e.g., the mechanical treatment of leather and skins, or partly mechanical, e.g., the treatment of water or the prevention of corrosion in general;
    • metallurgy, ferrous or non-ferrous alloys.
  • In all sections of the IPC, in the absence of an indication to the contrary, the Periodic System of chemical elements referred to is the one with 8 groups as represented in the table below. For example, group C07F 3/00   "Compounds containing elements of the 2nd Group of the Periodic System" refers to the elements of columns IIa and IIb.
    • In the case of operations, treatments, products or articles having both a chemical and a non-chemical part or aspect, the general rule is that the chemical part or aspect is covered by section C.
    • In some of these cases, the chemical part or aspect brings with it a non-chemical one, even though purely mechanical, because this latter aspect either is essential to the operation or treatment or constitutes an important element thereof. It has seemed, in fact, more logical not to dissociate the different parts or aspects of a coherent whole. This is the case for applied chemistry and for the industries, operations and treatments mentioned in Notes (1)(c), (d) and (e). For example, furnaces peculiar to the manufacture of glass are covered by class C03 and not by class F27 .
    • There are, however, some exceptions in which the mechanical (or non-chemical) aspect carries with it the chemical aspect, for example:
      • Certain extractive processes, in subclass A61K;
      • The chemical purification of air, in subclass A61L;
      • Chemical methods of fire-fighting, in subclass A62D;
      • Chemical processes and apparatus, in class B01;
      • Impregnation of wood, in subclass B27K;
      • Chemical methods of analysis or testing, in subclass G01N;
      • Photographic materials and processes, in class G03, and, generally, the chemical treatment of textiles and the production of cellulose or paper, in section D.
    • In still other cases, the pure chemical aspect is covered by section C and the applied chemical aspect by another section, such as A, B or F, e.g., the use of a substance or composition for:
      • treatment of plants or animals, covered by subclass A01N;
      • foodstuffs, covered by class A23;
      • ammunition or explosives, covered by class F42 .
    • When the chemical and mechanical aspects are so closely interlocked that a neat and simple division is not possible, or when certain mechanical processes follow as a natural or logical continuation of a chemical treatment, section C may cover, in addition to the chemical aspect, a part only of the mechanical aspect, e.g., after-treatment of artificial stone, covered by class C04 . In this latter case, a note or a reference is usually given to make the position clear, even if sometimes the division is rather arbitrary.
D SECTION D — TEXTILES; PAPER.
E SECTION E — FIXED CONSTRUCTIONS.
F SECTION F — MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING.
G SECTION G — PHYSICS.
Notes[n] G:
  • In this section, the following term is used with the meaning indicated:
    • "variable" (as a noun) means a feature or property (e.g., a dimension, a physical condition such as temperature, a quality such as density or colour) which, in respect of a particular entity (e.g., an object, a quantity of a substance, a beam of light) and at a particular instant, is capable of being measured; the variable may change, so that its numerical expression may assume different values at different times, in different conditions or in individual cases, but may be constant in respect of a particular entity in certain conditions or for practical purposes (e.g., the length of a bar may be regarded as constant for many purposes).
  • Attention is drawn to the definitions of terms or expressions used, appearing in the notes of several of the classes in this section, in particular those of "measuring" in class G01 and "control" and "regulation" in class G05 .
  • Classification in this section may present more difficulty than in other sections, because the distinction between different fields of use rests to a considerable extent on differences in the intention of the user rather than on any constructional differences or differences in the manner of use, and because the subjects dealt with are often in effect systems or combinations, which have features or parts in common, rather than "things", which are readily distinguishable as a whole. For example, information (e.g., a set of figures) may be displayed for the purpose of education or advertising (G09 ), for enabling the result of a measurement to be known (G01 ), for signalling the information to a distant point or for giving information which has been signalled from a distant point (G08 ). The words used to describe the purpose depend on features that may be irrelevant to the form of the apparatus concerned, for example, such features as the desired effect on the person who sees the display, or whether the display is controlled from a remote point. Again, a device which responds to some change in a condition, e.g., in the pressure of a fluid, may be used, without modification of the device itself, to give information about the pressure (G01L) or about some other condition linked to the pressure (another subclass of class G01, e.g., G01K for temperature), to make a record of the pressure or of its occurrence (G07C ), to give an alarm (G08B ), or to control another apparatus (G05 ).
    • The classification scheme is intended to enable things of a similar nature (as indicated above) to be classified together. It is therefore particularly necessary for the real nature of any technical subject to be decided before it can be properly classified.
H SECTION H — ELECTRICITY.
Notes[n] H:
  • These Notes cover the basic principles and general instructions for use of section H.
    • Section H covers :
      • basic electric elements, which cover all electric units and the general mechanical structure of apparatus and circuits, including the assembly of various basic elements into what are called printed circuits and also cover to a certain extent the manufacture of these elements (when not covered elsewhere);
      • generation of electricity, which covers the generation, conversion and distribution of electricity together with the controlling of the corresponding gear;
      • applied electricity, which covers :
        • general utilisation techniques, viz. those of electric heating and electric lighting circuits;
        • some special utilisation techniques, either electric or electronic in the strict sense, which are not covered by other sections of the Classification, including:
          • electric light sources, including lasers;
          • electric X-ray technique;
          • electric plasma technique and the generation and acceleration of electrically charged particles or neutrons;
      • basic electronic circuits and their control;
      • radio or electric communication technique;
      • the use of a specified material for the manufacture of the article or element described. In this connection, paragraphs   88 to   90 of the Guide should be referred to.
    • In this section, the following general rules apply:
      • Subject to the exceptions stated in I(c), above, any electric aspect or part peculiar to a particular operation, process, apparatus, object or article, classified in one of the sections of the Classification other than section H, is always classified in the subclass for that operation, process, apparatus, object or article. Where common characteristics concerning technical subjects of similar nature have been brought out at class level, the electric aspect or part is classified, in conjunction with the operation, process, apparatus, object or article, in a subclass which covers entirely the general electrical applications for the technical subject in question;
      • The electrical applications referred to under (a), above, either general or particular, include:
        • the therapeutic processes and apparatus, in class A61;
        • the electric processes and apparatus used in various laboratory or industrial operations, in classes B01 and B03 and in subclass B23K;
        • the electricity supply, electric propulsion and electric lighting of vehicles in general and of particular vehicles, in the subsection "Transporting" of section B;
        • the electric ignition systems of internal-combustion engines, in subclass F02P, and of combustion apparatus in general, in subclass F23Q;
        • the whole electrical part of section G, i.e. measuring devices including apparatus for measuring electric variables, checking, signalling and calculating. Electricity in that section is generally dealt with as a means and not as an end in itself;
      • All electrical applications, both general and particular, presuppose that the "basic electricity" aspect appears in section H (see I(a) above) as regards the electric "basic elements" which they comprise. This rule is also valid for applied electricity, referred to in I(c), above, which appears in section H itself.
    • In this section, the following special cases occur:
      • Among the general applications covered by sections other than section H, it is worth noting that electric heating in general is covered by subclasses F24D or F24H or class F27, and that electric lighting in general is partly covered by class F21, since in section H (see I(c), above) there are places in H05B which cover the same technical subjects;
      • In the two cases referred to under (a), above, the subclasses of section F, which deal with the respective subjects, essentially cover in the first place the whole mechanical aspect of the apparatus or devices, whereas the electrical aspect, as such, is covered by subclass H05B;
      • In the case of lighting, this mechanical aspect should be taken to cover the material arrangement of the various electric elements, i.e., their geometrical or physical position in relation to one another; this aspect is covered by subclass F21V, the elements themselves and the primary circuits remaining in section H. The same applies to electric light sources, when combined with light sources of a different kind. These are covered by subclass H05B, whereas the physical arrangement which their combination constitutes is covered by the various subclasses of class F21;
      • As regards heating, not only the electric elements and circuitry designs, as such, are covered by subclass H05B, but also the electric aspects of their arrangement, where these concern cases of general application; electric furnaces being considered as such. The physical disposition of the electric elements in furnaces is covered by section F. If a comparison is made with electric welding circuits, which are covered by subclass B23K in connection with welding, it can be seen that electric heating is not covered by the general rule stated in II, above.