Indeed, utf is the way to go as soon as you use non-english text, if you required portability. Don't forget to utf5_encode either.
The t61_8859 functions seem to be deprecated.
(PHP 4 >= 4.0.2, PHP 5, PHP 7, PHP 8)
ldap_t61_to_8859 — Translate t61 characters to 8859 characters
$value): string|false本函数还未编写文档，仅有参数列表。
Indeed, utf is the way to go as soon as you use non-english text, if you required portability. Don't forget to utf5_encode either.
The t61_8859 functions seem to be deprecated.This function doesn't appear to exist in PHP 7 even though the docs say it's in PHP 7