How did class 16.23 split?

Class 16.23, in its Rev. 2 form, split into two new classes in NACE Rev. 2.1: class 16.23, manufacture of other builders carpentry and joinery, and class 16.25, manufacture of doors and windows of wood. Paragraph 142 of the manual states the split. The old class number is reused for the residual class, and a new number carries the doors and windows work. The split does not determine a code for a specific reader.

What does the reuse of the number 16.23 mean?

The reuse of the number 16.23 for the residual class is a numbering decision, not a statement that the content is unchanged. The new class 16.23 covers other builders carpentry and joinery, with the word other signalling that the doors and windows work has been removed. The new class 16.25 covers manufacture of doors and windows of wood. The two titles together divide the old content into a specific class and a residual class, in the same pattern as other splits in the classification. A reader who assumes that 16.23 in Rev. 2.1 means the same as 16.23 in Rev. 2 has missed the removal, and will overstate the new class.

The numbering gap is also informative. The numbers in the group run 16.21, 16.22, 16.23, 16.24 in the detailed structure, with 16.25 added for the new class, and 16.26 to 16.28 for the split of the old class 16.29. The manual does not state a rule that class numbers must run without gaps, and this guide does not assert one. The gap, where a number exists in one version and not in the other, is a normal result of restructuring. The correspondence table, not the number sequence, is the record of how the old class relates to the new classes.

What must be checked in the explanatory notes?

Section 4 of the manual states the split and the two titles, and it does not reproduce the explanatory notes for the two classes. The notes are therefore the necessary next step, and this guide does not reproduce inclusion or exclusion lists that it has not verified from the notes. The note for class 16.25 states what counts as a door or window of wood for the class, including the treatment of multi material doors and windows, and the note for class 16.23 states what other builders carpentry and joinery covers after the removal. The notes for the neighbouring plastic and metal doors and windows classes, in divisions 22 and 25, state the material boundaries, and they must be read where the material of a door or window is mixed or unclear in general terms.

The caution about material boundaries is not speculative. The manual summary for the plastic split, in paragraph 144, creates a parallel class 22.23, manufacture of doors and windows of plastic, and the wood note for the old group, as printed in the manual, cross refers to manufacture of windows, shutters and French windows and their frames of wood, and to multi material doors and windows with the frame made of wood. The cross references show that the manual treats frame material as a relevant boundary, and that a door or window must be placed by the note for its material class, not by the word door or window alone. The notes for classes 16.23 and 16.25 are the authority for the wood side of that boundary.

How is the split shown?

| Result in NACE Rev. 2.1 | Title in the manual | Character |

|---|---|---|

| 16.23 | Manufacture of other builders carpentry and joinery | Residual class, number reused |

| 16.25 | Manufacture of doors and windows of wood | Specific class, new number |

The table follows paragraph 142. It states the two results and their character, and nothing more, because section 4 states nothing more about the split. A fuller account, with inclusions, exclusions and borderline cases, comes from the explanatory notes for the two classes and from the correspondence table entry for the old class. The table in this guide is a summary of the manual summary. It is not a substitute for the notes, and it must not be quoted as if it stated the content of either class.

What does a split not decide?

The titles quoted in this cluster are the titles in the Eurostat manual, in section 4 and in the detailed structure. A title states the heading of a category. The full content of the category is not stated here, and neither is it stated that an activity whose name resembles the title belongs in the category. The explanatory note governs the content, including the inclusions, exclusions and borderline cases the manual prints for the class. Before quoting the code for any purpose, read the note: a title alone is a heading, not the category.

Where is a split class confirmed?

The confirmation sequence is the note, then the table, then the holder of the record. The note states what the new class contains. The table states how the old class relates to the new classes. The entry held for a specific unit is stated by the institute or register. No step replaces another.

Note the reused number for the residual class, read the notes for both new classes before quoting either, and confirm the entry with the institute or register that holds it.