How do notes differ by level?

Notes differ by level in granularity, while sharing the same annotation forms. A section note states the broad scope of a section. A division note states the field inside the section, and can state an implementation rule for the division. A group note states the field inside the division, defining terms used in the group heading. A class note states the detailed inclusions and exclusions that divide the group. A note at a higher level frames the notes below it, and a note at a lower level divides the frame.

What does each level state?

A section note states the field in prose, with the main kinds of activity and the main boundary. The note for Section A states exploitation of vegetal and animal natural resources, with growing, raising, harvesting, and production of animal products, plus organic agriculture, aquaculture, and genetically modified crops and animals, and it excludes undifferentiated subsistence production by households, classified in class 98.10. A division note states the basic activities in the division, the division level inclusions and exclusions, and any implementation rule. The note for Division 01 states two basic activities, crop and animal production, the mixed farming exception, soilless cultivation, incidental services, hunting, and exclusions for processing, field construction, marketing associations, and landscape services, together with the implementation rule for own output processing.

A group note states the scope of the group, defining the term in the group heading. Group 01.1 states that non perennial crops are plants that do not last for more than two growing seasons, and that growing for seed production is included. Group 01.2 states that perennial crops are plants that last for more than two growing seasons, either dying back after each season or growing continuously, and that growing for seed production is included. A class note states the detailed lists. Class 01.11 lists cereals, leguminous crops and oil seeds, with examples, and excludes rice, sweetcorn, fodder crops, and oleaginous fruits, each with a cross reference. The granularity increases at each step down, while the forms, description, includes, includes also, and excludes, stay the same.

Level	Granularity in the verified agriculture notes
Section A	Broad field, main kinds of activity, main boundary to class 98.10
Division 01	Two basic activities, mixed farming exception, implementation rule, division exclusions
Group 01.1 and 01.2	Definition of non perennial and perennial, seed production included
Class 01.11	Detailed crop lists, examples, four exclusions with cross references

How are parent notes used to read a class note?

Parent notes are used to frame a class note, by stating the scope inside which the class sits, and by stating exclusions that apply to the whole parent. A class note must be read inside its group, division and section notes, because an exclusion at a higher level applies to every class below it, even where the class note does not repeat it. An activity that is excluded at division level, such as subsequent processing of agricultural products beyond preparation for primary markets, cannot be included at class level inside that division, even if a class heading shares words with the processing activity. The parent exclusion is part of the class scope, by nesting, and the class note must be read as the division scope divided, not as a standalone definition.

Parent notes also define terms used in the class heading. A class heading that uses a term defined in the group note, such as non perennial, must be read with the group definition, because the term carries the group meaning. A class heading that uses a term defined in the division note, such as mixed farming, must be read with the division statement of the exception. A reader who reads a class note without its parent notes will therefore miss definitions and exclusions that are stated only at the higher level, and will misread the class scope. The reading order is top down: section, division, group, class, with the index entry checked alongside the class note, and the correspondence table checked after the notes where a move is in question.

What happens when a level has no separate note?

The same point applies to a group that consists of a single group split at class level, where the group heading repeats the division heading. The group note, in that case, states the field at group level, and the class notes divide it. The repeated heading does not mean that the group and the division are the same category. They are categories at different levels, with the same heading by the rule for an unsplit level, and the class notes below the group state the division of the field. The level of a note is shown by its code and its place in the structure, not by its heading alone, and the code must be checked to find the level.

What do notes at different levels not do?

Notes at different levels do not, together, assign a code to a unit, and they do not confirm an entry. They define categories at each level, in a hierarchy, so that a category can be found by narrowing from section to class, with the scope stated at each step. The assignment of a unit, and the confirmation of an entry, remain separate steps, made by the institute or register that holds the record, applying the classification rules to the information held about the unit. A reader who has read the notes at all levels has learned how the classification describes an activity, at increasing granularity. That reader must still confirm an entry with the institute or register, and must not present a category found by narrowing as the entry for a specific business.

Read the section note, then the division, group and class notes in order, and confirm any entry with the national statistical institute or the business register that holds the record.