Tone Marks on POJ

[jilang]

Hi
When writing POJ with the proper tone marks, how do I know which letter of the word to put the mark on?

Thanks
~Jilang

[duaaagiii]

There are different schemes out there, but one that is gaining popularity is based on the sonority of the vowels. In this scheme, the diacritic is placed on the most sonorous vowel.

In order of decreasing sonority (ignoring nasality, m and ng):
a > oo > e > o > i > u

examples in POJ:
goá
Tâi-oân-lâng
boē-hiáu
tiān-oē
khoàⁿ tiān-iáⁿ