A speech variety is a collective name and is represented by a unique Speech Variety Code. There are three types of speech varieties: languages, dialects, or undetermined.
A language is defined in the Ethnologue based on the following criteria.
- Two related varieties are normally considered varieties of the same language if speakers of each variety have inherent understanding of the other variety at a functional level (that is, can understand based on knowledge of their own variety without needing to learn the other variety).
- Where spoken intelligibility between varieties is marginal, the existence of a common literature or a strong ethnolinguistic identity with a central variety that both can understand can be a strong indicator that they should nevertheless be considered varieties of the same language.
- Where there is enough intelligibility between varieties to enable communication, the existence of well established ethnolinguistic identities can be a strong indicator that they should nevertheless be considered to be different languages. Each language is identified by a standardized three-letter code that has been defined and published as the ISO 639-3 International Standard. A description of each language is found in the Ethnologue.
A dialect is defined by the Registry Of Dialects (ROD) as a specific variety of an ISO language that requires distinct media presentations (whether audio, video or print) in order to overcome barriers of understanding or acceptance. Determining factors may include differences in vocabulary, grammatical construction, idioms, and accents, as well as religious or social prejudices. Those speech varieties that qualify as dialects according to the above definition are identified with a ROD Code
Undetermined Speech Variaties do not fit the definition of either language or dialect. This means more language research is needed to determine if they are an alternate name for another language or dialect, or the name of a location where it is spoken, or there is another type of ambiguity.
Each speech variety has a unique GRN language name, and a corresponding GRN language number, assigned by the Language Tracking Department of Global Recordings Network. The data about all the speech varieties, with alternate names, ISO codes, locations, and much other information is stored in the Global Recordings Information Database or GRID.