Siddham? script is an abugida (standing for each letter exemplifying a consonant, whereas vowels are written with obligatory diacritics) or 'alphasyllabary' as opposed to an alphabet. This happens due to each character indicating a syllable, but not encompassing every possible syllable. If no other mark comes about, then the short 'a' is adopted and espoused. Diacritic marks designate the additional vowels, the pure nasal (anusvara) and the aspirated vowel (visarga). An extraordinary mark (virama) may be employed to designate that the letter stands alone with no accompaniment of vowel, which sometimes is the case at the termination of Sanskrit words.
Several of the Buddhist texts which were carried forth to China along the Silk Road (also popular as Silk Routes, the pathways are a wide-ranging interconnected network of trade routes spanning the Asian continent) were penned using a version of the Siddham? script. This chain network continued to develop and negligible variations are still witnessed across time and in umpteen regions. To state more importantly, the script was employed to carry and transfer the Buddhist tantra texts. The time that is being spoken of, it was deemed important to preserve the pronunciation of mantras and Chinese was not regarded as fit for writing the sounds of Sanskrit. This unique and intelligent movement led to the withholding of the Siddham? Script in East Asia. The practice of writing exploiting Siddham? survived in East Asia, where Tantric Buddhism is also known to have thrived consistently.
Kukai (also hugely esteemed posthumously as Kobo-Daishi, 774-835, he was a Japanese monk, scholar, poet and artist) was the man to introduce the Siddham? script in Japan when he returned from China in 806. Kukai had studied Sanskrit in China with Nalanda-trained monks, together with one recognised as Prajna. By the time Kukai had studied and memorised this script, trading and pilgrimage routes traversing land to India were closed by the expansion of Islamic empire of the Abbasids.
Leaving all such promising hindrances aside, Siddham? script is still basically represented as a hand-written script. The contemporary age has endeavoured to thrust some efforts to create computer fonts of this ancient inscription, though till date none of these are capable of reproducing all of Siddham? conjunct consonants just as it was previously.
Reading and writing a Siddham script calls for not only grasping the elementary vowels and consonants, but also learning how to amalgamate vowels with consonants, including how to cope with double and conjunct consonants. Examples of the last kind include: tta, mma, and rma, kya etc. Sanskrit also encompasses the vowels utilised by Siddham, but these are hardly ever employed in mantras and are often omitted from the alphabetical order in Siddham.
The Siddham script strictly utilises vowels and consonants, essentially including the ones designated during the Gupta rule.
The vowels are - a, i, u, r, e, ai, o, au
Vowel diacritics with ka - k, ka, ki, ku, kr, ke, kai, ko, kau
Consonants - ka, kha, ga, gha, na, ca, cha, ja, jha, ta, tha, da, dha, pa, pha, ba, bha, ma, ya, ra, la, va, sa, ha, ksa