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CommentsonEncodingDuplicateIndicCharacters

VinodhRajan

vrs3@standrews.ac.uk

ThisdocumentisinresponsetothefollowingrecentdocumentssubmittedtotheL2registry

authored by Shriramana Sharma Proposal to encode 0DF5Malayalam LetterArchaic II

(L2/12225)andProposaltoaddtwocharactersforBrahmi(L2/12226).

EncodingWrittenFormsasopposedtophonemesInL2/12225ShriramanaSharmarecommendsforencodinganarchaicformofMalayalam

Independentvowelletteru.ShriramanawritesUnicodeencodeswrittenformsandnot

thesounds thereof.Thesamemaxim isrepeatedatL2/12226aswell todisunifyTamil

specificBrahmicharactersLLA&VIRAMASIGN.Whilethestatementistrue,itmustalsobe

taken intoaccount, thatUnicodedoesntactually recommendencodingofall theglyphic

variantsofacharacteraswell.

TheIndicscriptsusuallyhavealternateindependentformsforseveralletters,whichcannot

bejustconsideredassimpleglyphicvariantsoftheirbaseforms.Itisnotpossibletoencode

allthosearchaicoralternateglyphsasindependentcharactersintheUCS.

Considerthebelowexamples:

Siddhami

u Devanagaria jha a Brahmi

L2/12-233

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Tamil

u

MostprobablythislatteralternateformofBrahmi (whichwasmoreprevalentinSouthernIndia&SriLanka)wasthesourceofthecorrespondingalternate letterform inSiddham&

Malayalam.

Quitesurprisingly,L2/12226doesntseem to requestan independentcodepoint for this

sourcevariant.

The interesting case is that of Tamil u is the oft used form, while derivedindependentlyfromthecorrespondingshortvoweluisthealternateform.Themaxim Unicode encodeswrittenforms andnot the sounds thereof cannotbeoverappliedtoeveryoneoftheexamplesabove.Anysuchapplicationwillprobablyresultinthe

encodingofalltheabovesampleglyphicvariantsasseparatecharactersintheUCS.

Suchamoveisquiteunwarranted.Thiswouldsetaseriousprecedenttoencodeadozenor

more glyphic variants as independent characters in the UCS. Paleographic origins of the

lettersareimmaterialfortheprocessofencoding.

Ondualencodingof/ra/inBengaliBlock&DevanagariPrishtamatraE

U+09F0&U+09B0wereneededtorepresenttwodifferentmodernlanguagesinplain

text.AsforPrishtamatraEsincetherewerereorderingsinvolved,thissubsequentlyposed

problems for therenderingengines.Both thecasesarenotpreciseprecedents toencode

furtherduplicatecharacters.

ForArchaicMalayalamII boththealternateglyphsbelongtothesamelanguage.

For theBrahmi additions,Brahmiblock is itselfhighlyunified in theUCSwhich requires

extensive tailoring for its implementation. In all probability, the Brahmi font has to be

customizedforasinglevariantanditcannotincorporateallthemyriadvariantsfoundinthe

inscriptions.

BrahmiSpecificDisUnifications

JustafewBrahmicharacterscannotbedisunifiedcitingindependentpaleographicorigins.

It must be noted that independent Bhattiprolu variants are already unified with the

existingcharacters.Asnotedearlier,whileL2/12256requeststhedisunificationofLLAand

VIRAMA, but it doesnt seem to recommend the disunification of the independent

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alternative .Therefore,anydisunification in theBrahmiblockneeds tobetakenonlyafterconsideringtheoverallunification/disunificationparadigmoftheentireblock.GraphemicSegmentationGraphemic Segmentation is quite complex for Indic scripts again requiring several

customizationsandisnotaverystrongargumenttodisunifytheVIRAMAforTamilBrahmi.

EvenforDevanagari(oranyotherIndicscript),therecannotbeasingleuniformgraphemic

segmentation. For the same word, //,

isoffivegraphemes,whileisoffourgraphemes,dependentontheconjunctbehavior. Therefore, even for the same word, behavior of the segmentation rules are

dictatedbythefont,andthereforemustbetakencareonlyattheapplicationlevel.

FontLevelHandlingAswithallglyphicvariations, thecharactersproposed inL2/12226&L2/12225mustbe

handledatthefontlevel.

Already, the Malayalam Classical font available as a part of Indolipi package

(http://www.aai.unihamburg.de/indtib/INDOLIPI/Indolipi.htm) has the alternate u at

U+0D08,andsupportsclassicalorthographyofMalayalamscriptsuchasextensiveconjunct

behavior,ligatedvowelsignsforU,UU,VocalicRandVocalicRRetc.

IncaseofBrahmi,asingle fontcannotpossiblysupportbothTamilvariantofBrahmiand

other Brahmi variants at the same time. As discussed earlier, the font needs to be

specifically tailored for theparticularBrahmivariant. In theabsenceof suchause case,

there are no possible issues in unifying the proposed new Brahmi characters with the

existingcharacters.

OpenTypesupportslanguagetags,andGraphitehasfeatureswhichcanbeenabled.Hence,

incasethereanyspecificcaseswhereboththevariantsmustbeusedinthesametext,the

abovecanbeharnessed.

Conclusion

Basedonalltheaforementionedarguments,theUTCshouldnotrecommendtheencoding

of the glyphic variants proposed in L2/12225 & L2/12226, and instead advice the

unificationofthecharacterswiththealreadyexistingcharacters,tobehandledatthefont

level.