Thanks ornanovitch.
tolgaaaltas
I guess you are right. Just found I got that extension install before, and tried just now. It supports only existing keys to translate for, unfortunately a tag name is not a key but a user input string. Furthermore, I believe the code (probably php) does not contain a translation wrap function to the tag name like ...->trans($tag->name) , looks like directly using $tag->name and $tag->description.
