Featural writing system

In a featural writing system, the shapes of the symbols (such as letters) are not arbitrary but encode phonological features of the phonemes that they represent. The term featural was introduced by Geoffrey Sampson to describe Hangul and Pitman shorthand.

Joe Martin introduced the term featural notation to describe writing systems that include symbols to represent individual features rather than phonemes. He asserts that "alphabets have no symbols for anything smaller than a phoneme".

A featural script represents finer detail than an alphabet. Here symbols do not represent whole phonemes, but rather the elements (features) that make up the phonemes, such as voicing or its place of articulation. Theoretically, each feature could be written with a separate letter; and abjads or abugidas, or indeed syllabaries, could be featural, but the only prominent system of this sort is Korean Hangul. In Hangul, the featural symbols are combined into alphabetic letters, and these letters are in turn joined into syllabic blocks, so that the system combines three levels of phonological representation.

Many scholars, e.g. John DeFrancis, reject this class or at least labeling Hangul as such. The Korean script is a conscious script creation by literate experts, which Daniels calls a "sophisticated grammatogeny". These include stenographies and constructed scripts of hobbyists and fiction writers (such as Tengwar), many of which feature advanced graphic designs corresponding to phonologic properties. The basic unit of writing in these systems can map to anything from phonemes to words. It has been shown that even the Latin script has sub-character "features".

...
Wikipedia