System.Security.Cryptography.DerEncoder.IsPrintableStringCharacter C# (CSharp) Method

        private static bool IsPrintableStringCharacter(char c)
        {
            // ITU-T X.680 (11/2008)
            // 41.4 (PrintableString)

            // Latin Capital, Latin Small, Digits
            if ((c >= 'A' && c <= 'Z') ||
                (c >= 'a' && c <= 'z') ||
                (c >= '0' && c <= '9'))
            {
                return true;
            }

            // Individually included characters
            switch (c)
            {
                case ' ':
                case '\'':
                case '(':
                case ')':
                case '+':
                case ',':
                case '-':
                case '.':
                case '/':
                case ':':
                case '=':
                case '?':
                    return true;
            }

            return false;
        }