Behaviour for letter-spacing in indic scripts

Dear Indic Layout Task Force,

There is a thread starting at 
http://lists.w3.org/Archives/Public/www-style/2014Jan/0438.html that 
discusses letter-spacing in indic scripts.

The current ilreq draft talks about letter-spacing at
http://www.w3cindia.in/Indic-req-draft/Indic-layout-requirements.html#letter-spac, 
however it doesn't clarify the situation where conjuncts are composed of 
multiple consonants.

My assumption is that this behaves much like justification, and my 
understanding of that is as follows:

If a conjunct doesn't display the virama, it's components and associated 
vowel-signs, diacritics, etc should be kept as a single unit, but 
otherwise the top bar is broken around each akshara.  For example, one 
would expect to see अंतर्राष्ट्रीयकरण [1] stretched as

अं त र्रा ष्ट्री य क र ण

If, however, the virama is displayed explicitly, one would expect to see 
the same word stretched as

अं त र् रा ष् ट् री य क र ण

(The latter corresponds to Unicode 'extended grapheme clusters', whereas 
the first does not.)

Could someone please confirm whether this is correct?

Thank you,
RI


[1] the word अंतर्राष्ट्रीयकरण is composed as follows:

U+0905 DEVANAGARI LETTER A
U+0902 DEVANAGARI SIGN ANUSVARA
U+0924 DEVANAGARI LETTER TA
U+0930 DEVANAGARI LETTER RA
U+094D DEVANAGARI SIGN VIRAMA
U+0930 DEVANAGARI LETTER RA
U+093E DEVANAGARI VOWEL SIGN AA
U+0937 DEVANAGARI LETTER SSA
U+094D DEVANAGARI SIGN VIRAMA
U+091F DEVANAGARI LETTER TTA
U+094D DEVANAGARI SIGN VIRAMA
U+0930 DEVANAGARI LETTER RA
U+0940 DEVANAGARI VOWEL SIGN II
U+092F DEVANAGARI LETTER YA
U+0915 DEVANAGARI LETTER KA
U+0930 DEVANAGARI LETTER RA
U+0923 DEVANAGARI LETTER NNA

Received on Friday, 25 April 2014 16:33:07 UTC