ⓘ Classification systems ..

Aarne–Thompson–Uther Index

The Aarne–Thompson–Uther Index is a catalogue of folktale types used in folklore studies. The ATU Index is the product of a series of revisions and expansions by an international group of scholars: Originally composed in German by Finnish folklorist Antti Aarne ; the index was translated into English, revised, and expanded by American folklorist Stith Thompson ; and later further revised and expanded by German folklorist Hans-Jorg Uther. Along with Thompsons Motif-Index of Folk-Literature, with which it is used in tandem, the ATU Index is an essential tool for folklorists.

ACM Computing Classification System

The ACM Computing Classification System is a subject classification system for computing devised by the Association for Computing Machinery. The system is comparable to the Mathematics Subject Classification in scope, aims, and structure, being used by the various ACM journals to organise subjects by area.

Active galactic nucleus

An active galactic nucleus is a compact region at the center of a galaxy that has a much higher than normal luminosity over at least some portion of the electromagnetic spectrum with characteristics indicating that the luminosity is not produced by stars. Such excess non-stellar emission has been observed in the radio, microwave, infrared, optical, ultra-violet, X-ray and gamma ray wavebands. A galaxy hosting an AGN is called an "active galaxy." The non-stellar radiation from an AGN is theorized to result from the accretion of matter by a supermassive black hole at the center of its host g ...


An Alisol is a Reference Soil Group of the World Reference Base for Soil Resources. Alisols have an argic horizon, which has a high cation exchange capacity. In the subsoil, the base saturation is low. There exist mixed forms, for example Stagnic Alisol, that are mainly Alisol, but also contain components that are found in Stagnosols. Alisols occur in tropical and humid subtropical climates, but are also found in temperate regions. Compared to Lixisols, Acrisols and Ferralsols, Alisols have much higher-activity clays and are likely to be found on younger terrains or more geologically activ ...

Alpine Club classification of the Eastern Alps

The Alpine Club classification of the Eastern Alps is a common division of the Eastern Alps into 75 mountain ranges, based on the Moriggl Classification first published in 1924 by the German and Austrian Alpine Club. The present-day division established for the German-speaking world was compiled by the German, Austrian and South Tyrol Alpine Clubs and published in 1984 and is also used for the basic numbering of Alpine Club maps for mountaineering.

Andre Walker Hair Typing System

The Andre Walker Hair Typing System is classification system for hair types created in the 1990s by Oprah Winfreys stylist Andre Walker. It was originally created to market Walkers line of hair care products but has since been widely adopted as a hair type classification system. The system includes images of each hair type to aid classification. The system has been criticised for an apparent hierarchy which values caucasian hair over other hair types. In 2018 the system was the subject of episodes of the podcasts 99% Invisible and The Stoop.


ⓘ Classification systems

  • notational system that represents the order of topics in the classification and allows items to be stored in that order. Library classification systems group
  • Climate classification systems are ways of classifying the world s climates. A climate classification may correlate closely with a biome category, as
  • Computing Classification System CCS is a subject classification system for computing devised by the Association for Computing Machinery ACM The system is
  • rating system for film classification Scientific classification disambiguation Biological classification of organisms Chemical classification Medical
  • support systems direct surveillance of epidemic or pandemic outbreaks There are country specific standards and international classification systems Many
  • Chemical ATC Classification System is a drug classification system that classifies the active ingredients of drugs according to the organ or system on which
  • century, the Swiss locomotive, multiple unit, motor coach and railcar classification system in either its original or updated forms, has been used to name
  • The Manual Ability Classification System MACS is a medical classification system used to describe how children aged from 4 to 18 years old with cerebral
  • classification system for locomotive wheel arrangements, the system is slightly different for steam and electric diesel vehicles. The French system counts