TheInternational Alphabet of Sanskrit Transliteration (IAST) is atransliteration scheme that allows the losslessromanisation ofIndic scripts as employed bySanskrit and related Indic languages. It is based on a scheme that emerged during the 19th century from suggestions byCharles Trevelyan,William Jones,Monier Monier-Williams and other scholars, and formalised by the Transliteration Committee of the GenevaOriental Congress, in September 1894.[1][2] IAST makes it possible for the reader to read the Indic text unambiguously, exactly as if it were in the original Indic script. It is this faithfulness to the original scripts that accounts for its continuing popularity amongst scholars.
Scholars commonly use IAST in publications that cite textual material in Sanskrit,Pāḷi and other classical Indian languages.
IAST is also used for major e-text repositories such as SARIT, Muktabodha, GRETIL, and sanskritdocuments.org.
The IAST scheme represents more than a century of scholarly usage in books and journals on classical Indian studies. By contrast, theISO 15919 standard for transliterating Indic scripts emerged in 2001 from the standards and library worlds. For the most part, ISO 15919 follows the IAST scheme, departing from it only in minor ways (e.g., ḷ/l̥ and ṛ/r̥)—see comparison below.
The IAST letters are listed with theirDevanagari equivalents and phonetic values inIPA, valid forSanskrit,Hindi and other modern languages that use Devanagari script, but some phonological changes have occurred:
Some letters are modified withdiacritics: Long vowels are marked with anoverline (often called amacron). Vocalic (syllabic) consonants, retroflexes and ṣ (/ʂ~ɕ~ʃ/) have anunderdot. Two letters have an overdot: ṁ and ṅ (/ŋ/). One has anacute accent: ś (/ʃ/). One letter has a line below: ḻ (/ɭ/) (Vedic).
UnlikeASCII-only romanisations such asITRANS orHarvard-Kyoto, the diacritics used for IAST allow capitalisation of proper names. The capital variants of letters never occurring word-initially (Ṁ Ṇ Ṅ Ñ Ṝ Ḹ) are useful only when writing in all-caps and inPāṇini contexts for which the convention is to typeset theIT sounds as capital letters.
For the most part, IAST is a subset ofISO 15919 that merges the retroflex (underdotted) liquids with the vocalic ones (ringed below) and the shortclose-mid vowels with the long ones. The following seven exceptions are from the ISO standard accommodating an extended repertoire of symbols to allow transliteration ofDevanāgarī and otherIndic scripts, as used for languages other than Sanskrit.
Devanāgarī
IAST
ISO 15919
Comment
ए / े
e
ē (e)
ISOe generally represents shortऎ / ॆ, but optionally represents longए / े in the Devanagari, Bengali, Gurmukhi, Gujarati, and Odia scripts.
ओ / ो
o
ō (o)
ISOo generally represents shortऒ / ॆ, but optionally represents longओ / ो in the Devanagari, Bengali, Gurmukhi, Gujarati, and Odia scripts.
ऎ / ॆ
ĕ
e
ISOe generally represents shortऎ / ॆ, but optionally represents longए / े in the Devanagari, Bengali, Gurmukhi, Gujarati, and Odia scripts. The IASTĕ represents shortऎ / ॆ.
ऒ / ॆ
ŏ
o
ISOo generally represents shortऒ / ॆ, but optionally represents longओ / ो in the Devanagari, Bengali, Gurmukhi, Gujarati, and Odia scripts. The IASTŏ represents shortऒ / ॆ.
The most convenient method of inputting romanized Sanskrit is by setting up an alternativekeyboard layout. This allows one to hold a modifier key to type letters with diacritical marks. For example,alt+a = ā. How this is set up varies by operating system.
Linux/Unix and BSD desktop environments allow one to set up custom keyboard layouts and switch them by clicking a flag icon in the menu bar.
macOS One can use the pre-installed US International keyboard, or install Toshiya Unebe's Easy Unicode keyboard layout.
Microsoft Windows Windows also allows one to change keyboard layouts and set up additional custom keyboard mappings for IAST. This Pali keyboard installer[5] made by Microsoft Keyboard Layout Creator (MSKLC) supports IAST (works on Microsoft Windows up to at least version 10, can use Alt button on the right side of the keyboard instead of Ctrl+Alt combination).
Many systems provide a way to select Unicode characters visually.ISO/IEC 14755 refers to this as ascreen-selection entry method.
Microsoft Windows has provided a Unicode version of the Character Map program (find it by hitting⊞ Win+R then typecharmap then hit↵ Enter) since version NT 4.0 – appearing in the consumer edition since XP. This is limited to characters in theBasic Multilingual Plane (BMP). Characters are searchable by Unicode character name, and the table can be limited to a particular code block. More advanced third-party tools of the same type are also available (a notablefreeware example isBabelMap).
macOS provides a "character palette" with much the same functionality, along with searching by related characters, glyph tables in a font, etc. It can beenabled in the input menu in the menu bar under System Preferences → International → Input Menu (or System Preferences → Language and Text → Input Sources) or can be viewed under Edit → Emoji & Symbols in many programs.
Users of SCIM on Linux based platforms can also have the opportunity to install and use the sa-itrans-iast input handler which provides complete support for the ISO 15919 standard for the romanization of Indic languages as part of the m17n library.
Or user can use some Unicode characters in Latin-1 Supplement, Latin Extended-A, Latin Extended Additional and Combining Diarcritical Marks block to write IAST.
This sectionneeds expansion. You can help byadding to it.(September 2016)
Only certainfonts support all the LatinUnicode characters essential for the transliteration of Indic scripts according to the IAST and ISO 15919 standards.
Many other text fonts commonly used for book production may be lacking in support for one or more characters from this block. Accordingly, many academics working in the area of Sanskrit studies make use of free OpenType fonts such as FreeSerif orGentium, both of which have complete support for the full repertoire of conjoined diacritics in the IAST character set. Released under theGNU FreeFont orSIL Open Font License, respectively, such fonts may be freely shared and do not require the person reading or editing a document to purchase proprietary software to make use of its associated fonts.
^abc"Tenth International Congress of Orientalists, Held at Geneva".The Journal of the Royal Asiatic Society of Great Britain and Ireland:879–892. 1895.JSTOR25207765.
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