What is the list of diacritics used to denote the seven Cantonese tones (in pinyin or similar notation)? Is there a standard (or even, more common) convention?
Common romanization systems for Cantonese are Jyutping, Cantonese Pinyin, and Yale.
In Yale, tones are either indicated with tone marks coupled with -h, or with numbers:
1 high-flat 55 sī sīn sīk 1 high-fall. 53 sì sìn 2 mid-rising 35 sí sín 3 mid-flat 33 si sin sik 4 mid-falling 21 sìh sìhn 5 low-rising 13 síh síhn 6 low-flat 22 sih sihn sihk