What does Section D cover in ISIC Rev. 5?

Section D in ISIC Rev. 5, published by the UN Statistics Division, covers the supply of electricity, gas, steam and air conditioning. It describes activities that produce and distribute those utilities through networks and related supply systems, rather than the construction of the networks or the manufacture of equipment. The section is organised around the utility supplied and the supply activity, so generation, transmission and distribution sit together as a supply story. Readers should treat Section D as a statistical description of supply activities, and confirm any code with the national statistical institute or business register that holds the record.

What holds Section D together as one section?

The thread is supply through a network. Electricity generated at a plant, gas moved through mains, steam piped to buildings, and cooled or heated air delivered through a system all share that pattern: produce or gather, move through a network, deliver to users on an ongoing basis. A municipal utility that generates electricity and sells it to households through a distribution network shows the pattern in its simplest form. Generation and distribution are not two unrelated businesses bolted together; they are stages of one supply service, and Section D groups them as such.

Which supply jobs are inside Section D?

The following kinds of work are described in ISIC Rev. 5, published by the UN Statistics Division, as part of this grouping:

• Electricity generation, transmission and distribution
• Manufacture and distribution of gas through mains
• Steam supply and air conditioning supply
• Sale of electric power and natural gas through intermediaries where described in Rev. 5
• Operation of utility supply networks for electricity and gas

That list is an orientation aid, not a substitute for the full class description. When the heading fits but the detail in section d does not, let the detail in the Rev. 5 publication prevail, and ask the national institute about a formal record. Notice how each item names a supply step or a network operation, not a building step or a manufacturing step. That consistency is the test for whether a new activity belongs here.

Where does Section D stop?

Building a power station, laying a pipeline and making a turbine belong in other parts of ISIC Rev. 5, published by the UN Statistics Division. Section D starts where supply through a network begins, and that boundary matters because the same physical asset can be linked to construction, manufacturing or supply at different stages of its life. A turbine is manufactured, then installed as part of construction, then operated as part of supply. A pipeline is laid, then operated. A power station is built, then run. At each stage the asset is the same object, but the work being done to it or with it has changed, and the classification tracks the work.

A firm that only installs wiring inside a building shows the boundary from the other side. Both that firm and a Section D utility touch electricity, but installation inside a building is not network supply. The installer creates or modifies wiring in one property. The utility operates a distribution network serving many users over time. Touching the same utility is not enough; operating the supply service is what counts.

How do the levels below Section D sharpen the picture?

Rev. 5, published by the UN Statistics Division, arranges section d as a ladder from broad sections to narrow classes. A section such as the one discussed here gives the broad field, a division narrows it, a group narrows it further, and a class describes a specific kind of activity. So, for section d, read a code by taking each level in turn, rather than guessing from the section letter alone. National versions may add further detail below the class, but the international structure provides the shared frame that lets similar supply work be counted together across countries, even when utilities are organised differently in each country.

Inside Section D, that downward reading separates, for example, generation from distribution, and electricity supply from steam supply, even though all of them share the section. A reader who stops at “Section D” knows only that the work concerns utility supply. A reader who follows the levels down knows which utility, which stage, and which kind of operation is being described.

What should you check before using a Section D description?

Use this guide as orientation to ISIC Rev. 5, published by the UN Statistics Division, and keep its limits in view. A description here cannot settle a particular unit’s code, and it cannot serve as a licence, a permission or a tax decision. Those questions belong to the statistical office, the business register and the relevant regulators, each in its own field.

For section d, each code statement in this guide comes from the UN Statistics Division classification detail and the ISIC Rev. 5 publication in the frontmatter.

As a closing guardrail, this guide describes a statistical classification only. It does not decide your code, your principal activity or your registration, so please confirm any of those with the national statistical institute or business register that holds your record.