I would like to ask 1) what is the function of the "ardhachandra" diacritic in Devanagari script. I see it used in transcribing English words (does it have other use?) where it is apparently used sometimes for English "a" and sometimes for "e" (I found it used in rendering of English "Catalan" and "genetics" in Devanagari). So what is its oficial proper usage? Is it used for any mid-front or mid-low vowel that is short? Or for long as well? 2) What are the "twisted" versions of Devanagari "e", "o", "ai" and "au" letters such as ऎ कॆ कॊ and the like? They have their own keys on the keyboard, so they seem to be understood as different characters from the ordinary "e", "o", "ai", "au". Contrary to that, they can be found in texts on the internet used where the ordinary ones normally stand. (like in the genitive postpositions "ke", "ko"!) So what is this?