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Inspec Classification

The Inspec classification is divided into five sections. Codes begin with
A, B, C, D or E where:

A = Physics
B = Electrical Engineering and Electronics
C = Computers and Control  
D = Information Technology for Business
E = Production, manufacturing & mechanical engineering

Please note: From 1 January 2020, we will no longer be using the subject classifications under “D: Information and Technology for Business” to index content in Inspec. All relevant content will continue to be indexed under other appropriate subject classifications. Section D codes will remain searchable for content indexed prior to this date.

The code format is typically: A7865K where

A = section of the database
  7 = highest or most general level of classification
    8 = second level of classification
       65 = third level of classification
             K = fourth or most specific level of classification (not all codes have the fourth level of classification)

You can view the brief outline to Inspec Classification below.

Outline of Inspec classification

Section A - Physics

  • General [A00]
  • The physics of elementary particles and fields [A10]
  • Nuclear physics [A20]
  • Atomic and molecular physics [A30]
  • Fundamental areas of phenomenology [A40]
  • Fluids, plasmas and electric discharges [A50]
  • Condensed matter: structure, thermal and mechanical properties [A60]
  • Condensed matter: electronic structure, electrical, magnetic, and optical properties [A70]
  • Cross-disciplinary physics and related areas of science and technology [A80]
  • Geophysics, astronomy and astrophysics [A90]

Section B - Electrical engineering and electronics

  • General topics, engineering mathematics and materials science [B00]
  • Circuit theory and circuits [B10]
    Components, electron devices and materials [B20]
  • Magnetic and superconducting materials and devices [B30]
  • Optical materials and applications, electro-optics and optoelectronics [B40]
  • Electromagnetic fields [B50]
  • Communications [B60]
  • Instrumentation and special applications [B70]
  • Power systems and applications [B80]

Section C - Computers and control

  • General and management topics [C00]
  • Systems and control theory [C10]
  • Control technology [C30]
  • Numerical analysis and theoretical computer topics [C40]
  • Computer hardware [C50]
  • Computer software [C60]
  • Computer applications [C70]

Section D - Information technology for business

  • General and management aspects [D10]
  • Applications [D20]
  • General systems and equipment [D30]
  • Office automation - communications [D40]
  • Office automation - computing [D50]

Section D classifications are applied to relevant content indexed up to 31 December 2019 inclusive. Please see other relevant classifications for content indexed after this date.

Section E - Mechanical and production

  • Engineering [E00]
  • Manufacturing and production [E10]
  • Engineering mechanics [E20]
  • Industrial sectors [E30]

Truncating Codes

On most platforms, all codes starting with A78, e.g. A7865, A7865K are also indexed A78. As a result, you do not have to use truncation to retrieve a group of codes starting with A78. However, if the required code is longer than three characters, you do need to use truncation. For example:

  • A7865 Optical properties of thin films and low-dimensional structures
  • A7865E Optical properties of metals and metallic alloys (thin films/low-dimensional structures)
  • A7865H Optical properties of elemental semiconductors (thin films/low-dimensional structures)
  • A7865K Optical properties of II-VI and III-V semiconductors (thin films/low-dimensional structures)
  • A7865M Optical properties of amorphous and glassy semiconductors and insulators (thin films/low-dimensional structures)
  • A7865P Optical properties of other inorganic semiconductors and insulators (thin films/low-dimensional structures)
  • A7865T Optical properties of organic compounds and polymers (thin films/low-dimensional structures)
  • A7865V Optical properties of fullerenes and related materials (thin films/low-dimensional structures)

In the above example, the classification code ‘a7865’ will retrieve only records which deal with optical properties of thin films and low-dimensional structures in general whereas ‘A7865?’ (where? signifies truncation) will retrieve also all records which deal with elemental semiconductors, fullerenes, etc.


At least one classification code is assigned for the main subject matter of each record and additional codes may be assigned for subsidiary subjects.
Codes are always assigned to the most specific level possible and can be assigned from one or more of the four sections of the database depending
upon the subject matter.