diff --git a/Classes/PHPExcel/Calculation/Engineering.php b/Classes/PHPExcel/Calculation/Engineering.php
index 0e5246cd..9e26004c 100644
--- a/Classes/PHPExcel/Calculation/Engineering.php
+++ b/Classes/PHPExcel/Calculation/Engineering.php
@@ -49,6 +49,11 @@ define('EULER', 2.71828182845904523536);
  */
 class PHPExcel_Calculation_Engineering {
 
+	/**
+	 * Details of the Units of measure that can be used in CONVERTUOM()
+	 *
+	 * @var mixed[]
+	 */
 	private static $_conversionUnits = array( 'g'		=> array(	'Group'	=> 'Mass',			'Unit Name'	=> 'Gram',						'AllowPrefix'	=> True		),
 											  'sg'		=> array(	'Group'	=> 'Mass',			'Unit Name'	=> 'Slug',						'AllowPrefix'	=> False	),
 											  'lbm'		=> array(	'Group'	=> 'Mass',			'Unit Name'	=> 'Pound mass (avoirdupois)',	'AllowPrefix'	=> False	),
@@ -114,6 +119,11 @@ class PHPExcel_Calculation_Engineering {
 											  'lt'		=> array(	'Group'	=> 'Liquid',		'Unit Name'	=> 'Litre',						'AllowPrefix'	=> True		)
 											);
 
+	/**
+	 * Details of the Multiplier prefixes that can be used with Units of Measure in CONVERTUOM()
+	 *
+	 * @var mixed[]
+	 */
 	private static $_conversionMultipliers = array(	'Y'	=> array(	'multiplier'	=> 1E24,	'name'	=> 'yotta'	),
 													'Z'	=> array(	'multiplier'	=> 1E21,	'name'	=> 'zetta'	),
 													'E'	=> array(	'multiplier'	=> 1E18,	'name'	=> 'exa'	),
@@ -136,6 +146,11 @@ class PHPExcel_Calculation_Engineering {
 													'y'	=> array(	'multiplier'	=> 1E-24,	'name'	=> 'yocto'	)
 												 );
 
+	/**
+	 * Details of the Units of measure conversion factors, organised by group
+	 *
+	 * @var mixed[]
+	 */
 	private static $_unitConversions = array(	'Mass'		=> array(	'g'		=> array(	'g'		=> 1.0,
 																							'sg'	=> 6.85220500053478E-05,
 																							'lbm'	=> 2.20462291469134E-03,
@@ -670,6 +685,14 @@ class PHPExcel_Calculation_Engineering {
 											);
 
 
+	/**
+	 * _parseComplex
+	 *
+	 * Parses a complex number into its real and imaginary parts, and an I or J suffix
+	 *
+	 * @param	string		$complexNumber	The complex number
+	 * @return	string[]	Indexed on "real", "imaginary" and "suffix"
+	 */
 	public static function _parseComplex($complexNumber) {
 		$workString = (string) $complexNumber;
 
@@ -717,6 +740,14 @@ class PHPExcel_Calculation_Engineering {
 	}	//	function _parseComplex()
 
 
+	/**
+	 * _cleanComplex
+	 *
+	 * Cleans the leading characters in a complex number string
+	 *
+	 * @param	string		$complexNumber	The complex number to clean
+	 * @return	string		The "cleaned" complex number
+	 */
 	private static function _cleanComplex($complexNumber) {
 		if ($complexNumber{0} == '+') $complexNumber = substr($complexNumber,1);
 		if ($complexNumber{0} == '0') $complexNumber = substr($complexNumber,1);
@@ -1604,11 +1635,17 @@ class PHPExcel_Calculation_Engineering {
 	/**
 	 * COMPLEX
 	 *
-	 * returns a complex number of the form x + yi or x + yj.
+	 * Converts real and imaginary coefficients into a complex number of the form x + yi or x + yj.
 	 *
-	 * @param	float		$realNumber
-	 * @param	float		$imaginary
-	 * @param	string		$suffix
+	 * Excel Function:
+	 *		COMPLEX(realNumber,imaginary[,places])
+	 *
+	 * @access	public
+	 * @category Engineering Functions
+	 * @param	float		$realNumber		The real coefficient of the complex number.
+	 * @param	float		$imaginary		The imaginary coefficient of the complex number.
+	 * @param	string		$suffix			The suffix for the imaginary component of the complex number.
+	 *										If omitted, the suffix is assumed to be "i".
 	 * @return	string
 	 */
 	public static function COMPLEX($realNumber=0.0, $imaginary=0.0, $suffix='i') {
@@ -1651,8 +1688,14 @@ class PHPExcel_Calculation_Engineering {
 	 *
 	 * Returns the imaginary coefficient of a complex number in x + yi or x + yj text format.
 	 *
-	 * @param	string		$complexNumber
-	 * @return	real
+	 * Excel Function:
+	 *		IMAGINARY(complexNumber)
+	 *
+	 * @access	public
+	 * @category Engineering Functions
+	 * @param	string		$complexNumber	The complex number for which you want the imaginary
+	 * 										coefficient.
+	 * @return	float
 	 */
 	public static function IMAGINARY($complexNumber) {
 		$complexNumber	= PHPExcel_Calculation_Functions::flattenSingleValue($complexNumber);
@@ -1667,8 +1710,13 @@ class PHPExcel_Calculation_Engineering {
 	 *
 	 * Returns the real coefficient of a complex number in x + yi or x + yj text format.
 	 *
-	 * @param	string		$complexNumber
-	 * @return	real
+	 * Excel Function:
+	 *		IMREAL(complexNumber)
+	 *
+	 * @access	public
+	 * @category Engineering Functions
+	 * @param	string		$complexNumber	The complex number for which you want the real coefficient.
+	 * @return	float
 	 */
 	public static function IMREAL($complexNumber) {
 		$complexNumber	= PHPExcel_Calculation_Functions::flattenSingleValue($complexNumber);
@@ -1683,8 +1731,11 @@ class PHPExcel_Calculation_Engineering {
 	 *
 	 * Returns the absolute value (modulus) of a complex number in x + yi or x + yj text format.
 	 *
-	 * @param	string		$complexNumber
-	 * @return	real
+	 * Excel Function:
+	 *		IMABS(complexNumber)
+	 *
+	 * @param	string		$complexNumber	The complex number for which you want the absolute value.
+	 * @return	float
 	 */
 	public static function IMABS($complexNumber) {
 		$complexNumber	= PHPExcel_Calculation_Functions::flattenSingleValue($complexNumber);
@@ -1698,10 +1749,14 @@ class PHPExcel_Calculation_Engineering {
 	/**
 	 * IMARGUMENT
 	 *
-	 * Returns the argument theta of a complex number, i.e. the angle in radians from the real axis to the representation of the number in polar coordinates.
+	 * Returns the argument theta of a complex number, i.e. the angle in radians from the real
+	 * axis to the representation of the number in polar coordinates.
 	 *
-	 * @param	string		$complexNumber
-	 * @return	string
+	 * Excel Function:
+	 *		IMARGUMENT(complexNumber)
+	 *
+	 * @param	string		$complexNumber	The complex number for which you want the argument theta.
+	 * @return	float
 	 */
 	public static function IMARGUMENT($complexNumber) {
 		$complexNumber	= PHPExcel_Calculation_Functions::flattenSingleValue($complexNumber);
@@ -1731,7 +1786,10 @@ class PHPExcel_Calculation_Engineering {
 	 *
 	 * Returns the complex conjugate of a complex number in x + yi or x + yj text format.
 	 *
-	 * @param	string		$complexNumber
+	 * Excel Function:
+	 *		IMCONJUGATE(complexNumber)
+	 *
+	 * @param	string		$complexNumber	The complex number for which you want the conjugate.
 	 * @return	string
 	 */
 	public static function IMCONJUGATE($complexNumber) {
@@ -1742,7 +1800,11 @@ class PHPExcel_Calculation_Engineering {
 		if ($parsedComplex['imaginary'] == 0.0) {
 			return $parsedComplex['real'];
 		} else {
-			return self::_cleanComplex(self::COMPLEX($parsedComplex['real'], 0 - $parsedComplex['imaginary'], $parsedComplex['suffix']));
+			return self::_cleanComplex( self::COMPLEX( $parsedComplex['real'],
+													   0 - $parsedComplex['imaginary'],
+													   $parsedComplex['suffix']
+													 )
+									  );
 		}
 	}	//	function IMCONJUGATE()
 
@@ -1752,8 +1814,11 @@ class PHPExcel_Calculation_Engineering {
 	 *
 	 * Returns the cosine of a complex number in x + yi or x + yj text format.
 	 *
-	 * @param	string		$complexNumber
-	 * @return	string
+	 * Excel Function:
+	 *		IMCOS(complexNumber)
+	 *
+	 * @param	string		$complexNumber	The complex number for which you want the cosine.
+	 * @return	string|float
 	 */
 	public static function IMCOS($complexNumber) {
 		$complexNumber	= PHPExcel_Calculation_Functions::flattenSingleValue($complexNumber);
@@ -1773,8 +1838,11 @@ class PHPExcel_Calculation_Engineering {
 	 *
 	 * Returns the sine of a complex number in x + yi or x + yj text format.
 	 *
-	 * @param	string		$complexNumber
-	 * @return	string
+	 * Excel Function:
+	 *		IMSIN(complexNumber)
+	 *
+	 * @param	string		$complexNumber	The complex number for which you want the sine.
+	 * @return	string|float
 	 */
 	public static function IMSIN($complexNumber) {
 		$complexNumber	= PHPExcel_Calculation_Functions::flattenSingleValue($complexNumber);
@@ -1794,7 +1862,10 @@ class PHPExcel_Calculation_Engineering {
 	 *
 	 * Returns the square root of a complex number in x + yi or x + yj text format.
 	 *
-	 * @param	string		$complexNumber
+	 * Excel Function:
+	 *		IMSQRT(complexNumber)
+	 *
+	 * @param	string		$complexNumber	The complex number for which you want the square root.
 	 * @return	string
 	 */
 	public static function IMSQRT($complexNumber) {
@@ -1820,7 +1891,10 @@ class PHPExcel_Calculation_Engineering {
 	 *
 	 * Returns the natural logarithm of a complex number in x + yi or x + yj text format.
 	 *
-	 * @param	string		$complexNumber
+	 * Excel Function:
+	 *		IMLN(complexNumber)
+	 *
+	 * @param	string		$complexNumber	The complex number for which you want the natural logarithm.
 	 * @return	string
 	 */
 	public static function IMLN($complexNumber) {
@@ -1848,7 +1922,10 @@ class PHPExcel_Calculation_Engineering {
 	 *
 	 * Returns the common logarithm (base 10) of a complex number in x + yi or x + yj text format.
 	 *
-	 * @param	string		$complexNumber
+	 * Excel Function:
+	 *		IMLOG10(complexNumber)
+	 *
+	 * @param	string		$complexNumber	The complex number for which you want the common logarithm.
 	 * @return	string
 	 */
 	public static function IMLOG10($complexNumber) {
@@ -1871,7 +1948,10 @@ class PHPExcel_Calculation_Engineering {
 	 *
 	 * Returns the common logarithm (base 10) of a complex number in x + yi or x + yj text format.
 	 *
-	 * @param	string		$complexNumber
+	 * Excel Function:
+	 *		IMLOG2(complexNumber)
+	 *
+	 * @param	string		$complexNumber	The complex number for which you want the base-2 logarithm.
 	 * @return	string
 	 */
 	public static function IMLOG2($complexNumber) {
@@ -1894,7 +1974,10 @@ class PHPExcel_Calculation_Engineering {
 	 *
 	 * Returns the exponential of a complex number in x + yi or x + yj text format.
 	 *
-	 * @param	string		$complexNumber
+	 * Excel Function:
+	 *		IMEXP(complexNumber)
+	 *
+	 * @param	string		$complexNumber	The complex number for which you want the exponential.
 	 * @return	string
 	 */
 	public static function IMEXP($complexNumber) {
@@ -1923,8 +2006,11 @@ class PHPExcel_Calculation_Engineering {
 	 *
 	 * Returns a complex number in x + yi or x + yj text format raised to a power.
 	 *
-	 * @param	string		$complexNumber
-	 * @param	float		$realNumber
+	 * Excel Function:
+	 *		IMPOWER(complexNumber,realNumber)
+	 *
+	 * @param	string		$complexNumber	The complex number you want to raise to a power.
+	 * @param	float		$realNumber		The power to which you want to raise the complex number.
 	 * @return	string
 	 */
 	public static function IMPOWER($complexNumber,$realNumber) {
@@ -1955,9 +2041,12 @@ class PHPExcel_Calculation_Engineering {
 	 *
 	 * Returns the quotient of two complex numbers in x + yi or x + yj text format.
 	 *
-	 * @param	string		$complexDividend
-	 * @param	string		$complexDivisor
-	 * @return	real
+	 * Excel Function:
+	 *		IMDIV(complexDividend,complexDivisor)
+	 *
+	 * @param	string		$complexDividend	The complex numerator or dividend.
+	 * @param	string		$complexDivisor		The complex denominator or divisor.
+	 * @return	string
 	 */
 	public static function IMDIV($complexDividend,$complexDivisor) {
 		$complexDividend	= PHPExcel_Calculation_Functions::flattenSingleValue($complexDividend);
@@ -1996,9 +2085,12 @@ class PHPExcel_Calculation_Engineering {
 	 *
 	 * Returns the difference of two complex numbers in x + yi or x + yj text format.
 	 *
-	 * @param	string		$complexNumber1
-	 * @param	string		$complexNumber2
-	 * @return	real
+	 * Excel Function:
+	 *		IMSUB(complexNumber1,complexNumber2)
+	 *
+	 * @param	string		$complexNumber1		The complex number from which to subtract complexNumber2.
+	 * @param	string		$complexNumber2		The complex number to subtract from complexNumber1.
+	 * @return	string
 	 */
 	public static function IMSUB($complexNumber1,$complexNumber2) {
 		$complexNumber1	= PHPExcel_Calculation_Functions::flattenSingleValue($complexNumber1);
@@ -2026,8 +2118,11 @@ class PHPExcel_Calculation_Engineering {
 	 *
 	 * Returns the sum of two or more complex numbers in x + yi or x + yj text format.
 	 *
-	 * @param	array of mixed		Data Series
-	 * @return	real
+	 * Excel Function:
+	 *		IMSUM(complexNumber[,complexNumber[,...]])
+	 *
+	 * @param	string		$complexNumber,...	Series of complex numbers to add
+	 * @return	string
 	 */
 	public static function IMSUM() {
 		// Return value
@@ -2059,8 +2154,11 @@ class PHPExcel_Calculation_Engineering {
 	 *
 	 * Returns the product of two or more complex numbers in x + yi or x + yj text format.
 	 *
-	 * @param	array of mixed		Data Series
-	 * @return	real
+	 * Excel Function:
+	 *		IMPRODUCT(complexNumber[,complexNumber[,...]])
+	 *
+	 * @param	string		$complexNumber,...	Series of complex numbers to multiply
+	 * @return	string
 	 */
 	public static function IMPRODUCT() {
 		// Return value
@@ -2091,9 +2189,15 @@ class PHPExcel_Calculation_Engineering {
 	 * DELTA
 	 *
 	 * Tests whether two values are equal. Returns 1 if number1 = number2; returns 0 otherwise.
+	 * Use this function to filter a set of values. For example, by summing several DELTA
+	 * functions you calculate the count of equal pairs. This function is also known as the
+	 * Kronecker Delta function.
 	 *
-	 * @param	float		$a
-	 * @param	float		$b
+	 * Excel Function:
+	 *		DELTA(a[,b])
+	 *
+	 * @param	float		$a	The first number.
+	 * @param	float		$b	The second number. If omitted, b is assumed to be zero.
 	 * @return	int
 	 */
 	public static function DELTA($a, $b=0) {
@@ -2107,10 +2211,16 @@ class PHPExcel_Calculation_Engineering {
 	/**
 	 * GESTEP
 	 *
-	 * Returns 1 if number = step; returns 0 (zero) otherwise
+	 * Excel Function:
+	 *		GESTEP(number[,step])
 	 *
-	 * @param	float		$number
-	 * @param	float		$step
+	 * Returns 1 if number >= step; returns 0 (zero) otherwise
+	 * Use this function to filter a set of values. For example, by summing several GESTEP
+	 * functions you calculate the count of values that exceed a threshold.
+	 *
+	 * @param	float		$number		The value to test against step.
+	 * @param	float		$step		The threshold value.
+	 *									If you omit a value for step, GESTEP uses zero.
 	 * @return	int
 	 */
 	public static function GESTEP($number, $step=0) {
@@ -2153,6 +2263,9 @@ class PHPExcel_Calculation_Engineering {
 	 *
 	 * Returns the error function integrated between lower_limit and upper_limit
 	 *
+	 * Excel Function:
+	 *		ERF(lower[,upper])
+	 *
 	 * @param	float		$lower	lower bound for integrating ERF
 	 * @param	float		$upper	upper bound for integrating ERF.
 	 *								If omitted, ERF integrates between zero and lower_limit
@@ -2217,6 +2330,9 @@ class PHPExcel_Calculation_Engineering {
 	 *
 	 * Returns the complementary ERF function integrated between x and infinity
 	 *
+	 * Excel Function:
+	 *		ERF(x)
+	 *
 	 * @param	float		$x		The lower bound for integrating ERF
 	 * @return	int
 	 */
@@ -2294,9 +2410,16 @@ class PHPExcel_Calculation_Engineering {
 	/**
 	 * CONVERTUOM
 	 *
-	 * @param	float		$value
-	 * @param	string		$fromUOM
-	 * @param	string		$toUOM
+	 * Converts a number from one measurement system to another.
+	 * For example, CONVERT can translate a table of distances in miles to a table of distances
+	 * in kilometers.
+	 *
+	 * Excel Function:
+	 *		CONVERT(value,fromUOM,toUOM)
+	 *
+	 * @param	float		$value		The value in fromUOM to convert.
+	 * @param	string		$fromUOM	The units for value.
+	 * @param	string		$toUOM		The units for the result.
 	 * @return	float
 	 */
 	public static function CONVERTUOM($value, $fromUOM, $toUOM) {
diff --git a/Classes/PHPExcel/Calculation/Financial.php b/Classes/PHPExcel/Calculation/Financial.php
index f97693c4..ee0bfb69 100644
--- a/Classes/PHPExcel/Calculation/Financial.php
+++ b/Classes/PHPExcel/Calculation/Financial.php
@@ -52,20 +52,36 @@ define('FINANCIAL_PRECISION', 1.0e-08);
  */
 class PHPExcel_Calculation_Financial {
 
-	private static function _lastDayOfMonth($testDate) {
-		$date = clone $testDate;
-		$date->modify('+1 day');
-		return ($date->format('d') == 1);
+	/**
+	 * _lastDayOfMonth
+	 *
+	 * Returns a boolean TRUE/FALSE indicating if this date is the last date of the month
+	 *
+	 * @param	DateTime	$testDate	The date for testing
+	 * @return	boolean
+	 */
+	private static function _lastDayOfMonth($testDate)
+	{
+		return ($testDate->format('d') == $testDate->format('t'));
 	}	//	function _lastDayOfMonth()
 
 
-	private static function _firstDayOfMonth($testDate) {
-		$date = clone $testDate;
-		return ($date->format('d') == 1);
-	}	//	function _lastDayOfMonth()
+	/**
+	 * _firstDayOfMonth
+	 *
+	 * Returns a boolean TRUE/FALSE indicating if this date is the first date of the month
+	 *
+	 * @param	DateTime	$testDate	The date for testing
+	 * @return	boolean
+	 */
+	private static function _firstDayOfMonth($testDate)
+	{
+		return ($testDate->format('d') == 1);
+	}	//	function _firstDayOfMonth()
 
 
-	private static function _coupFirstPeriodDate($settlement, $maturity, $frequency, $next) {
+	private static function _coupFirstPeriodDate($settlement, $maturity, $frequency, $next)
+	{
 		$months = 12 / $frequency;
 
 		$result = PHPExcel_Shared_Date::ExcelToPHPObject($maturity);
@@ -86,7 +102,8 @@ class PHPExcel_Calculation_Financial {
 	}	//	function _coupFirstPeriodDate()
 
 
-	private static function _validFrequency($frequency) {
+	private static function _validFrequency($frequency)
+	{
 		if (($frequency == 1) || ($frequency == 2) || ($frequency == 4)) {
 			return true;
 		}
@@ -98,7 +115,22 @@ class PHPExcel_Calculation_Financial {
 	}	//	function _validFrequency()
 
 
-	private static function _daysPerYear($year,$basis) {
+	/**
+	 * _daysPerYear
+	 *
+	 * Returns the number of days in a specified year, as defined by the "basis" value
+	 *
+	 * @param	integer		$year	The year against which we're testing
+	 * @param   integer		$basis	The type of day count:
+	 *									0 or omitted US (NASD)	360
+	 *									1						Actual (365 or 366 in a leap year)
+	 *									2						360
+	 *									3						365
+	 *									4						European 360
+	 * @return	integer
+	 */
+	private static function _daysPerYear($year, $basis=0)
+	{
 		switch ($basis) {
 			case 0 :
 			case 2 :
@@ -109,11 +141,7 @@ class PHPExcel_Calculation_Financial {
 				$daysPerYear = 365;
 				break;
 			case 1 :
-				if (PHPExcel_Calculation_DateTime::_isLeapYear($year)) {
-					$daysPerYear = 366;
-				} else {
-					$daysPerYear = 365;
-				}
+				$daysPerYear = (PHPExcel_Calculation_DateTime::_isLeapYear($year)) ? 366 : 365;
 				break;
 			default	:
 				return PHPExcel_Calculation_Functions::NaN();
@@ -122,7 +150,8 @@ class PHPExcel_Calculation_Financial {
 	}	//	function _daysPerYear()
 
 
-	private static function _interestAndPrincipal($rate=0, $per=0, $nper=0, $pv=0, $fv=0, $type=0) {
+	private static function _interestAndPrincipal($rate=0, $per=0, $nper=0, $pv=0, $fv=0, $type=0)
+	{
 		$pmt = self::PMT($rate, $nper, $pv, $fv, $type);
 		$capital = $pv;
 		for ($i = 1; $i<= $per; ++$i) {
@@ -137,14 +166,31 @@ class PHPExcel_Calculation_Financial {
 	/**
 	 * ACCRINT
 	 *
-	 * Returns the discount rate for a security.
+	 * Returns the accrued interest for a security that pays periodic interest.
 	 *
-	 * @param	mixed	issue		The security's issue date.
-	 * @param	mixed	firstinter	The security's first interest date.
-	 * @param	mixed	settlement	The security's settlement date.
-	 * @param	float	rate		The security's annual coupon rate.
-	 * @param	float	par			The security's par value.
-	 * @param	int		basis		The type of day count to use.
+	 * Excel Function:
+	 *		ACCRINT(issue,firstinterest,settlement,rate,par,frequency[,basis])
+	 *
+	 * @access	public
+	 * @category Financial Functions
+	 * @param	mixed	$issue			The security's issue date.
+	 * @param	mixed	$firstinterest	The security's first interest date.
+	 * @param	mixed	$settlement		The security's settlement date.
+	 *									The security settlement date is the date after the issue date
+	 *									when the security is traded to the buyer.
+	 * @param	float	$rate			The security's annual coupon rate.
+	 * @param	float	$par			The security's par value.
+	 *									If you omit par, ACCRINT uses $1,000.
+	 * @param	float	$frequency		the number of coupon payments per year.
+	 *									Valid frequency values are:
+	 *										1	Annual
+	 *										2	Semi-Annual
+	 *										4	Quarterly
+	 *									If working in Gnumeric Mode, the following frequency options are
+	 *									also available
+	 *										6	Bimonthly
+	 *										12	Monthly
+	 * @param	int		$basis			The type of day count to use.
 	 *										0 or omitted	US (NASD) 30/360
 	 *										1				Actual/actual
 	 *										2				Actual/360
@@ -152,9 +198,10 @@ class PHPExcel_Calculation_Financial {
 	 *										4				European 30/360
 	 * @return	float
 	 */
-	public static function ACCRINT($issue, $firstinter, $settlement, $rate, $par=1000, $frequency=1, $basis=0) {
+	public static function ACCRINT($issue, $firstinterest, $settlement, $rate, $par=1000, $frequency=1, $basis=0)
+	{
 		$issue		= PHPExcel_Calculation_Functions::flattenSingleValue($issue);
-		$firstinter	= PHPExcel_Calculation_Functions::flattenSingleValue($firstinter);
+		$firstinterest	= PHPExcel_Calculation_Functions::flattenSingleValue($firstinterest);
 		$settlement	= PHPExcel_Calculation_Functions::flattenSingleValue($settlement);
 		$rate		= (float) PHPExcel_Calculation_Functions::flattenSingleValue($rate);
 		$par		= (is_null($par))		? 1000 :	(float) PHPExcel_Calculation_Functions::flattenSingleValue($par);
@@ -181,12 +228,18 @@ class PHPExcel_Calculation_Financial {
 	/**
 	 * ACCRINTM
 	 *
-	 * Returns the discount rate for a security.
+	 * Returns the accrued interest for a security that pays interest at maturity.
 	 *
+	 * Excel Function:
+	 *		ACCRINTM(issue,settlement,rate[,par[,basis]])
+	 *
+	 * @access	public
+	 * @category Financial Functions
 	 * @param	mixed	issue		The security's issue date.
-	 * @param	mixed	settlement	The security's settlement date.
+	 * @param	mixed	settlement	The security's settlement (or maturity) date.
 	 * @param	float	rate		The security's annual coupon rate.
 	 * @param	float	par			The security's par value.
+	 *									If you omit par, ACCRINT uses $1,000.
 	 * @param	int		basis		The type of day count to use.
 	 *										0 or omitted	US (NASD) 30/360
 	 *										1				Actual/actual