the i18n-ascii.txt file came with pathauto module does not include all vietnamse characters, add this list to the file and all should be OK.
á = "a"
Á = "a"
à = "a"
À = "a"
ả = "a"
Ả = "a"
ã = "a"
à = "a"
ạ = "a"
Ạ = "a"
ă = "a"
Ă = "a"
ắ = "a"
Ắ = "a"
ằ = "a"
Ằ = "a"
ẳ = "a"
Ẳ = "a"
ẵ = "a"
Ẵ = "a"
ặ = "a"
Ặ = "a"
â = "a"
 = "a"
ầ = "a"
Ầ = "a"
ấ = "a"
Ấ = "a"
ẩ = "a"
Ẩ = "a"
ẫ = "a"
Ẫ = "a"
ậ = "a"
Ậ = "a"
é = "e"
É = "e"
è = "e"
È = "e"
ẻ = "e"
Ẻ = "e"
ẽ = "e"
Ẽ = "e"
ẹ = "e"
Ẹ = "e"
ê = "e"
Ê = "e"
ế = "e"
Ế = "e"
ề = "e"
Ề = "e"
ể = "e"
Ể = "e"
ễ = "e"
Ễ = "e"
ệ = "e"
Ệ = "e"
í = "i"
Í = "i"
ì = "i"
Ì = "i"
ỉ = "i"
Ỉ = "i"
ĩ = "i"
Ĩ = "i"
ị = "i"
Ị = "i"
ó = "o"
Ó = "o"
ò = "o"
Ò = "o"
ỏ = "o"
Ỏ = "o"
õ = "o"
Õ = "o"
ọ = "o"
Ọ = "o"
ô = "o"
Ô = "o"
ố = "o"
Ố = "o"
ồ = "o"
Ồ = "o"
ổ = "o"
Ổ = "o"
ỗ = "o"
Ỗ = "o"
ộ = "o"
Ộ = "o"
ơ = "o"
Ơ = "o"
ớ = "o"
Ớ = "o"
ờ = "o"
Ờ = "o"
ở = "o"
Ở = "o"
ỡ = "o"
Ỡ = "o"
ợ = "o"
Ợ = "o"
ú = "u"
Ú = "u"
ù = "u"
Ù = "u"
ủ = "u"
Ủ = "u"
ũ = "u"
Ũ = "u"
ụ = "u"
Ụ = "u"
ư = "u"
Ư = "u"
ứ = "u"
Ứ = "u"
ừ = "u"
Ừ = "u"
ử = "u"
Ử = "u"
ữ = "u"
Ữ = "u"
ự = "u"
Ự = "u"
Comments
Nice
Nice
trungso.com - PHP programming service
Thanks
Many thanks for this list.
I'm making a website for Jewell Gemstones and found out Pathauto didn't transliterate the Vietnamese characters. At first I thought it didn't work at all. After I found out only most Vietnamese special characters are not included i searched Google and find your list. Thanks so much, you saved me a lot of time.
I am so excited because I will launch the Drupal version of Jewell next week thanks to problem with Pathauto is now solved.