International standard ISO 2145 defines a typographic convention for the "numbering of divisions and subdivisions in written documents". It applies to any kind of document, including manuscripts, books, journal articles, and standards.
The ISO 2145 numbering scheme is defined by the following rules:
A table of contents might look like:
| 0 | Foreword |
| 1 | Introduction |
| 2 | Methodology |
| 2.1 | Counting techniques |
| 2.1.1 | Manual procedures |
| 2.1.1.1 | Counting apples |
| 2.1.1.2 | Counting oranges |
| 2.1.2 | Automatic methods |
| 2.2 | Quality control |
| 3 | Results |
| 4 | Related work |
| 4.1 | Bean counting |
| 4.2 | Sheep counting |
| 5 | Conclusions |
Division and subdivision numbers are cited in written text as in:
In spoken language, the full stops are omitted:
