If we create a thread here in Arabic language and give it a title "الموضوع العربية".
Typical URL will look something like:
URL encoded string for Arabic text is (%D8%A7%D9%84%D9%85%D9%88%D8%B6%D9%88%D8%B9-%D8%A7%D9%84%D8%B9%D8%B1%D8%A8%D9%8A%D8%A9)
It would be lot nicer if we can customize it something like: (transliteration)
And we can do it using an add-on at the time of thread creation (with the help of some translation/transliteration tools) or manually by thread creator in a custom optional field or later by moderators.
Having such a custom thread field will also enable us to have external content shown in our forum with their titles linked to the original source (if permalink field has and absolute external URI). An example will be to news/blog feeds. There we can parse the feeds and save a cached copy in our forum but link titles in the post listing to the actual source.