Found this solution helpful for Icelandic: I dug around the WordPress code and found the replacement function. It’s called remove_accents and is in the file wp-includes/formatting.php. There, right before the line “// Decompositions for Latin Extended-A” I added the following code:
chr(195).chr(144) => ‘D’, chr(195).chr(176) => ‘d’,
chr(195).chr(158) => ‘TH’,chr(195).chr(190) => ‘th’,
chr(195).chr(134) => ‘AE’,chr(195).chr(166) => ‘ae’,
Now the characters are replaced automatically like this: Ð => D, ð => d, Þ => TH, þ => th, Æ => AE, æ => ae. I don’t know if everyone has this problem, or if it just has to do with the character set settings on my webhost but this works great for me. No more manually fixing page slugs!
