[4] However, the Modern-Tamil standard allowed a few additional consonants from Grantha into its alphabet: ஜ (ja), ஷ (ṣa), ஸ (sa), ஹ (ha).
However if one were to include non-South-Dravidian words in their text, using the pure-Tamil script can cause errors in pronunciations since the phonemic-transcription rules of Tamil Grammar does not apply to such vocabularies.
Purists classify Middle Tamil as belonging to the latter class, thereby enabling the Dravidian movement to call Tamil-Grantha as impure.
[citation needed] Since Modern-Tamil unicode does not support all the missing consonants from Extended-Tamil, generally it is not possible to digitally encode it easily.
Tamil script can also be extended with ஃ (ஆய்த எழுத்து, āyda eḻuttu, equivalent to nuqta) to represent phonemes of foreign languages, especially used to write Islamic and Christian texts.