Relationships

The AGROVOC thesaurus organizes the overall descriptors into a six-layer hierarchical structure comprised of base descriptors and relationships between them. The following different relations may link various descriptors:
 
BT
    Broader term
    indicates a parent descriptor i.e. one level higher in the thesaurus structure. A broader descriptor is more general. For example Industrial emissions is the broader term for Industrial effluents;
NT
    Narrower term
    indicates one or more child descriptors i.e. one level lower in the thesaurus structure. A narrower descriptor is more specific. For example Industrial effluents has narrower terms Solid wastes and Liquid wastes.
RT
    Related term
    indicates other related descriptors. For example Industrial effluents is associated with the descriptor Sewage because industrial effluents may be discharged into a municipal collection system. This relation indicates that also other similar terms may be used in describing an information source.
UF
    Used for
    There may be also links between descriptors and non-descriptors. The relation UF (Used for) indicates "synonyms" of a given descriptor.

    Note: The non-descriptors should never be used for describing an information source; they simply provide the descriptor which should be used.

In addition there may be a scope note related to a descriptor (SN) which provides an explanation on using the given descriptor.