Apache is functioning normally

_SERVER["SERVER_ADDR"]

internationalized domain name (IDN)

multi-byte Unicode
    public UnicodeSet getNumberRepresentatives(String identifier) {
        int cp;
        UnicodeSet numerics = new UnicodeSet();
        for (int i = 0; i < identifier.length(); i += Character.charCount(i)) {
            cp = Character.codePointAt(identifier, i);
            // Store a representative character for each kind of decimal digit
            switch (UCharacter.getType(cp)) {
            case UCharacterCategory.DECIMAL_DIGIT_NUMBER:
                // Just store the zero character as a representative for comparison. 
                // Unicode guarantees it is cp - value.
                numerics.add(cp - UCharacter.getNumericValue(cp));
                break;
            case UCharacterCategory.OTHER_NUMBER:
            case UCharacterCategory.LETTER_NUMBER:
                throw new IllegalArgumentException("Should not be in identifiers.");
            }
        } 
        return numerics;
    }
...
    UnicodeSet numerics = getMixedNumbers(String identifier);
    if (numerics.size() > 1) reject(identifer, numerics);