Analysis of information sources in references of the Wikipedia article "Chú âm phù hiệu" in Vietnamese language version.
韻符「ㄭ」,陰平調號「¯」,注音時省略不標{...}陰平 以一短橫代表高平之聲調,注音時可省略不標。標注在字音最後一個符號右上角。
the rhyme symbol, "ㄭ", and the mark of Yin-ping tone, "¯", could be left out on Bopomofo notes.{...}This high and level tone is noted as a short dash mark and could be left out in Bopomofo note. If it is noted, it should be put on the upper right corner of the last Bopomofo note.