I am a little confused by the call for a review of UTS #39, Unicode Security Mechanisms (PRI #273). Are we being requested to report long-encoded 'restricted' characters in high frequency modern use? 'Restricted' refers to the classification in xidmodifications.txt.
One linked pair of long-encoded restricted characters in high frequency use is U+0E33 THAI CHARACTER SARA AM and U+0EB3 LAO VOWEL SIGN AM, which occurs in the extremely common Thai and Lao words for 'water' or 'liquid in general' น้ำ ນ້ຳ whose NFKC decompositions are the nonsensical forms น้ํา ນ້ໍາ, but may be faked by the linguistically incorrect นํ้า ນໍ້າ. In Thai the encodings are <U+0E19 THAI CHARACTER NO NU, U+0E49 THAI CHARACTER MAI THO, U+0E33 THAI CHARACTER SARA AM>, <U+0E19, U+0E49, U+0E4D THAI CHARACTER NIKHAHIT, U+0E32 THAI CHARACTER SARA AA> and <U+0E19, U+0E49, U+0E4D, U+0E49, U+0E32>. Now, U+0E4D THAI CHARACTER NIKHAHIT is classified as 'allowed; recommended', although its main use is in writing Pali, which would suggest that it should be 'restricted; historic' or 'restricted; limited-use'. The situation is not so clear for Lao - U+0ECD LAO NIGGAHITA is a fairly common vowel in the Lao language. To me, a truly bizarre set of 'restricted' characters is U+17CB KHMER SIGN BANTOC to U+17D0 KHMER SIGN SAMYOK SANNYA, which are categorised as 'restricted; technical'. They are all in use in the Khmer language. U+17CB KHMER SIGN BANTOC is required for the main methods of writing the Khmer vowels /a/ and /ɑ/. U+17CC KHMER SIGN ROBAT is a repha, but I would be surprised to learn that it has recently become little-used. It is, however, readily confused with U+17CC KHMER SIGN TOANDAKHIAT, a 'pure killer' whose main modern use is to show that a consonant is silent, rather like the Thai letter U+0E4C THAI CHARACTER THANTHAKHAT. (The names are the same.) The confusion arises because Sanskrit -rCa was pronounced /-r/ in Khmer, and final /r/ recently became silent in Khmer, so the effect of the Sanskrit /r/ is now to silence the final consonant. While U+17CE KHMER SIGN KAKABAT and U+17CF KHMER SIGN AHSDA may not be common, they are still in modern use. Although U+17D0 KHMER SIGN SAMYOK SANNYA may have declined in frequency, it has not dropped out of use and is still a common enough way of writing the vowel /a/. Richard. _______________________________________________ Unicode mailing list [email protected] http://unicode.org/mailman/listinfo/unicode
