Mapping Between ISO 639 and the SIL Ethnologue Principles Used and Lessons Learned

In Constable and Simons 2000, we discussed various issues that must be addressed in any system of language identification. The most significant issues among these focused on matters of definition: stating explicitly the operational definition of “language” being assumed, making clear the type of category (language, language cluster, dialect, etc.) each identifier represents, and documenting explicitly what each identifier denotes. In addition, we found indications of the existing ISO standards having problems in relation to each of these areas.