iiop-openjdk/src/main/java/org/wildfly/iiop/openjdk/rmi/Util.java
private static boolean isLegalIDLIdentifierChar(char c) {
        if (c >= 0x61 && c <= 0x7a)
            return true; // lower case letter

        if (c >= 0x30 && c <= 0x39)
            return true; // digit

        if (c >= 0x41 && c <= 0x5a)
            return true; // upper case letter

        if (c == '_')
            return true; // underscore

        return false;
    }
private static boolean isLegalIDLIdentifierChar(char c) {
        if (c >= 0x61 && c <= 0x7a)
            return true; // lower case letter

        if (c >= 0x30 && c <= 0x39)
            return true; // digit

        if (c >= 0x41 && c <= 0x5a)
            return true; // upper case letter

        if (c == '_')
            return true; // underscore

        return false;
    }
Determine if a <code>char</code> is a legal IDL identifier character.