List of writing systems

Ideographic scripts (in which graphemes are ideograms representing concepts or ideas rather than a specific word in a language) and pictographic scripts (in which the graphemes are iconic pictures) are not thought to be able to express all that can be communicated by language, as argued by the linguists John DeFrancis and J. Marshall Unger.

Although a few pictographic or ideographic scripts exist today, there is no single way to read them because there is no one-to-one correspondence between symbol and language.

In Japanese a similar system plays a minor role in foreign borrowings; for example, [tu] is written [to]+[u], and [ti] as [te]+[i].

The Tartessian or Southwestern script is typologically intermediate between a pure alphabet and the Paleohispanic full semi-syllabaries.

A segmental script has graphemes which represent the phonemes (basic unit of sound) of a language.

A featural script has elements that indicate the components of articulation, such as bilabial consonants, fricatives, or back vowels.

An abugida, or alphasyllabary, is a segmental script in which vowel sounds are denoted by diacritical marks or other systematic modification of the consonants.

The vast majority of abugidas are found from India to Southeast Asia and belong historically to the Brāhmī family, however the term is derived from the first characters of the abugida in Ge'ez: አ (A) ቡ (bu) ጊ (gi) ዳ (da) — (compare with alphabet).

In some cases, such as Meroitic, the sound values of the glyphs are known, but the texts still cannot be read because the language is not understood.

There are doubts that the Indus script is writing, and the Phaistos Disc has so little content or context that its nature is undetermined.

Comparatively recent manuscripts and other texts written in undeciphered (and often unidentified) writing systems; some of these may represent ciphers of known languages or hoaxes.