Classification structure

The structure of ANZSCO has five hierarchical levels - major group, sub-major group, minor group, unit group and occupation. The categories at the most detailed level of the classification are termed 'occupations'. These are grouped together to form 'unit groups', which in turn are grouped into 'minor groups'. Minor groups are aggregated to form 'sub-major groups' which in turn are aggregated at the highest level to form 'major groups'.

The following is a profile of the ANZSCO structure with hierarchy descriptions and examples. The complete listing of the major, sub-major, minor and unit groups and occupations can be found under the Browse Classification section.

Each major group comprises a different number of sub-major, minor and unit groups and occupations. The following table illustrates the distribution of these categories between the major groups.

One, two, three, four and six-digit codes are assigned to the major, sub-major, minor and unit groups, and occupations respectively.

Within each major group, the sub-major groups are ordered firstly by skill level and then alphabetically. Note: the various updates to ANZSCO have disrupted this practice as new occupations and unit groups have been assigned the next available code in the respective unit group or minor group. Residual 'other' sub-major groups are listed last. Sub-major groups comprising occupations at multiple skill levels have been ordered firstly on the basis of their highest predominant skill level, then alphabetically.

Within each sub-major group, the minor groups are ordered alphabetically, with the exception of residual 'miscellaneous' minor groups which are listed last. Similarly, within each minor group, the unit groups are ordered alphabetically, with the exception of the residual 'other' unit groups which are listed last.

The occupations within each unit group are essentially in alphabetical order, with the exception of 'general' occupations which are listed first, and residual 'not elsewhere classified' (nec) categories which are listed last. This ordering is more expedient than necessary and it is not considered that the addition of any new occupations, which may disrupt this ordering, will affect the usefulness of the classification.

The occupational profile of Australia and New Zealand is likely to change over time due to factors such as technological change and changes in the industrial profile of Australia and New Zealand. Therefore, from time to time, it may be necessary to add or delete occupations from the list of occupations separately identified in ANZSCO.

If it becomes necessary to identify an additional unit group or occupation, it will be allocated the next available four or six-digit code in the numerical sequence of codes of the minor or unit group to which it is being added. Similarly, if a unit group or occupation ceases to have sufficient numbers of persons employed to justify it continuing to be separately identified in the classification and it is consequently deleted from the classification, its code would not be reallocated as this would be likely to cause confusion with time series data.

It should be noted that the separately identified occupations are not allocated codes ending with the digits '0' or '9'. These are special purpose codes used to denote supplementary or operational (not further defined) codes in the case of '0' and residual (not elsewhere classified) categories in the case of '9' (see Supplementary or operational codes and Codes reserved for residual categories).

The ANZSCO code scheme is devised so that any future changes to the classification structure can be easily accommodated. However, in order that the classification remains a standard, users should not make arbitrary changes to the structure. Rather, they should contact the ABS or Statistics NZ and identify any apparent problems they encounter in the course of implementation, data collection or data analysis. ANZSCO will be revised at a suitable time so that all users continue to use the standard classification.

For each unit group of the classification structure, a six-digit code, consisting of the four digits of the unit group followed by the digits '99', is reserved as a residual 'not elsewhere classified' (nec) category. All occupations which are not separately identified in the classification structure are included in the 'nec' category of the unit group to which they relate. Residual categories are only identified in the classification structure if they are needed. ANZSCO currently identifies 84 'nec' categories.

The decision to include particular occupations in an 'nec' category rather than as substantive categories is based on their lack of numerical significance in Australia or New Zealand.

For each minor group, codes are reserved for residual categories at the unit group level. These codes consist of the minor group code followed by '9'. These categories are termed 'Other' and consist of separately identified occupations which do not fit into any of the unit groups contained within the minor group, on the basis of the classification criteria. The classification contains 22 'other' categories at the unit group level.

For each sub-major group, codes are also reserved for residual categories at the minor group level. These codes consist of the sub-major group code followed by '9'. These categories are termed 'Miscellaneous' and consist of separately identified unit groups which do not fit into any of the minor groups contained within the sub-major group, on the basis of the classification criteria. The classification contains eight 'miscellaneous' categories at the minor group level.

For each major group, codes are reserved for residual categories at the sub-major group level. These codes consist of the major group code followed by '9'. These categories are termed 'Other' and consist of separately identified minor groups which do not fit into any of the sub-major groups contained within the major group, on the basis of the classification criteria. The classification contains three 'other' categories at the sub-major group level.

Residual categories are part of the ANZSCO structure. They should not be created or used merely to 'dump' responses that cannot be coded to any separately identified category in the classification because of insufficient detail in the response. See Supplementary or operational codes.

Supplementary or operational codes are used in statistical collections to process inadequately described responses or for responses which are outside of the scope of the classification.

In Australia, these codes are of two types:

• six digit codes ending in two, three, four or five zeros; and
• six digit codes commencing with one zero.

Codes ending in zero are described as 'not further defined' (nfd) codes and are used to code responses which cannot be coded to the occupation level of the classification, but which can be coded to a higher level of the classification structure.

For example, responses which cannot be identified as relating directly to a particular occupation category, but which are known to be within the range of occupations within a particular unit group are coded to that unit group. Such responses are allocated an nfd code consisting of the four-digit code of the unit group followed by '00'. For instance, the response 'Internal Medicine Specialist' does not contain sufficient information to be coded directly to any particular occupation category, but it can be coded to Unit Group 2533 Specialist Physicians, which encompasses all internal medicine specialists. It is thus allocated the code 253300 Specialist Physicians, nfd.

Codes commencing with zero are used to process responses which do not provide sufficient information to be coded to any level of the structure. They are also used to process responses such as 'housewife', 'pensioner' and 'student', which are not covered by the current definition of the labour force (see Standards for Labour Force Statistics, ABS cat. no. 1288.0). The standard set of such codes used in the ANZSCO Coding Index is available on request from the ABS.

Other codes commencing with zero may be defined by users to facilitate the processing and storage of data, when data sets coded to ANZSCO contain records for entities outside the scope of ANZSCO. For example, occupational activities which are wholly illegal in New Zealand and all States and Territories of Australia are excluded from ANZSCO.

In New Zealand, codes commencing with the digits '99' are used as supplementary or operational codes.

• The code '997000' is used for legitimate/valid responses, such as 'public servant', which cannot be coded to any single occupation category because there is insufficient supporting information to accurately code to a specific category. This code is called 'Response Unidentifiable'.
• The code '999000' is used for responses, such as 'housewife', 'pensioner' or 'student', which are not covered by the current definition of the labour force. This code is called 'Response Outside Scope'.
• The code '999999' is used for non-response. This code is called 'Not Stated'.

It should be noted that supplementary or operational codes are not part of the classification structure. They exist for operational reasons only, and no data would be coded to them if sufficiently detailed responses or responses within the scope of the classification were obtained in all instances.

The detailed structure of ANZSCO at each descending level of the classification can be found under the Data downloads section. This also shows the relationship between the groups and skill level.

The first three tables (Major Groups, Sub-Major Groups and Minor Groups) show the predominant skill levels applying to each group.

In the next two tables (Unit Groups and Occupations), all skill levels applying to each group are shown.

A definitive list of all skill levels applying to each group in the classification is found in the definition for that group. See Definitions.