PHPOffice / PhpSpreadsheet

        // bit: 4-6; mask: 0x00000070; error type

        $errorStyle = (0x00000070 & $options) >> 4;

        switch ($errorStyle) {

            case 0x00:

                $errorStyle = DataValidation::STYLE_STOP;

                break;

            case 0x01:

                $errorStyle = DataValidation::STYLE_WARNING;

                break;

            case 0x02:

                $errorStyle = DataValidation::STYLE_INFORMATION;

                break;

        }

        // bit: 7; mask: 0x00000080; 1= formula is explicit (only applies to list)

        // I have only seen cases where this is 1

                // error style

                $errorStyle = 0x00;

                switch ($dataValidation->getErrorStyle()) {

                    case DataValidation::STYLE_STOP:

                        $errorStyle = 0x00;

                        break;

                    case DataValidation::STYLE_WARNING:

                        $errorStyle = 0x01;

                        break;

                    case DataValidation::STYLE_INFORMATION:

                        $errorStyle = 0x02;

                        break;

                }

                $options |= $errorStyle << 4;