BTW, Erik asked today how other search engines handle this kind of variation. Looks like some of the big U.S. ones don't.
The first two items on line 5 are:
- ខ្មែរ ≅ kh + m + e + r gives 198M results on Google and 11M results on Bing.
- ខែ្មរ ≅ kh + e + m + r gives 317K results on Google and 115K results on Bing.
Note that the first form is more correct because the characters are (typed) in pronunciation order, though both look the same to everyone.
Baidu gets it right, though the exact string affects ranking: ខ្មែរ vs ខែ្មរ—both get 639K results. In the second case, the second result is higher because it is an exact match.