Vendor/phpspreadsheet/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Reader/Xls.php
private function readDefinedName()
    {
        $length = self::getUInt2d($this->data, $this->pos + 2);
        $recordData = $this->readRecordData($this->data, $this->pos + 4, $length);

        // move stream pointer to next record
        $this->pos += 4 + $length;

        if ($this->version == self::XLS_BIFF8) {
            // retrieves named cells

            // offset: 0; size: 2; option flags
            $opts = self::getUInt2d($recordData, 0);

            // bit: 5; mask: 0x0020; 0 = user-defined name, 1 = built-in-name
            $isBuiltInName = (0x0020 & $opts) >> 5;

            // offset: 2; size: 1; keyboard shortcut

            // offset: 3; size: 1; length of the name (character count)
            $nlen = ord($recordData[3]);

            // offset: 4; size: 2; size of the formula data (it can happen that this is zero)
            // note: there can also be additional data, this is not included in $flen
            $flen = self::getUInt2d($recordData, 4);

            // offset: 8; size: 2; 0=Global name, otherwise index to sheet (1-based)
            $scope = self::getUInt2d($recordData, 8);

            // offset: 14; size: var; Name (Unicode string without length field)
            $string = self::readUnicodeString(substr($recordData, 14), $nlen);

            // offset: var; size: $flen; formula data
            $offset = 14 + $string['size'];
            $formulaStructure = pack('v', $flen) . substr($recordData, $offset);

            try {
                $formula = $this->getFormulaFromStructure($formulaStructure);
            } catch (PhpSpreadsheetException $e) {
                $formula = '';
            }

            $this->definedname[] = [
                'isBuiltInName' => $isBuiltInName,
                'name' => $string['value'],
                'formula' => $formula,
                'scope' => $scope,
            ];
        }
    }
private function readDefinedName()
    {
        $length = self::getUInt2d($this->data, $this->pos + 2);
        $recordData = $this->readRecordData($this->data, $this->pos + 4, $length);

        // move stream pointer to next record
        $this->pos += 4 + $length;

        if ($this->version == self::XLS_BIFF8) {
            // retrieves named cells

            // offset: 0; size: 2; option flags
            $opts = self::getUInt2d($recordData, 0);

            // bit: 5; mask: 0x0020; 0 = user-defined name, 1 = built-in-name
            $isBuiltInName = (0x0020 & $opts) >> 5;

            // offset: 2; size: 1; keyboard shortcut

            // offset: 3; size: 1; length of the name (character count)
            $nlen = ord($recordData[3]);

            // offset: 4; size: 2; size of the formula data (it can happen that this is zero)
            // note: there can also be additional data, this is not included in $flen
            $flen = self::getUInt2d($recordData, 4);

            // offset: 8; size: 2; 0=Global name, otherwise index to sheet (1-based)
            $scope = self::getUInt2d($recordData, 8);

            // offset: 14; size: var; Name (Unicode string without length field)
            $string = self::readUnicodeString(substr($recordData, 14), $nlen);

            // offset: var; size: $flen; formula data
            $offset = 14 + $string['size'];
            $formulaStructure = pack('v', $flen) . substr($recordData, $offset);

            try {
                $formula = $this->getFormulaFromStructure($formulaStructure);
            } catch (PhpSpreadsheetException $e) {
                $formula = '';
            }

            $this->definedname[] = [
                'isBuiltInName' => $isBuiltInName,
                'name' => $string['value'],
                'formula' => $formula,
                'scope' => $scope,
            ];
        }
    }
DEFINEDNAME.

This record is part of a Link Table. It contains the name
and the token array of an internal defined name. Token
arrays of defined names contain tokens with aberrant
token classes.

--    "OpenOffice.org's Documentation of the Microsoft
Excel File Format"