diff --git a/src/PhoneNumberUtil.php b/src/PhoneNumberUtil.php
index 38b3e8db4..922bddb00 100644
--- a/src/PhoneNumberUtil.php
+++ b/src/PhoneNumberUtil.php
@@ -91,7 +91,7 @@ class PhoneNumberUtil
 
     // The FIRST_GROUP_PATTERN was originally set to $1 but there are some countries for which the
     // first group is not used in the national pattern (e.g. Argentina) so the $1 group does not match
-    // correctly.  Therefore, we use \d, so that the first group actually used in the pattern will be
+    // correctly. Therefore, we use \d, so that the first group actually used in the pattern will be
     // matched.
     const FIRST_GROUP_PATTERN = "(\\$\\d)";
     // Constants used in the formatting rules to represent the national prefix, first group and
@@ -101,7 +101,7 @@ class PhoneNumberUtil
     const CC_STRING = '$CC';
 
     // A pattern that is used to determine if the national prefix formatting rule has the first group
-    // only, i.e., does not start with the national prefix. Note that the pattern explicitly allows
+    // only, i.e, does not start with the national prefix. Note that the pattern explicitly allows
     // for unbalanced parentheses.
     const FIRST_GROUP_ONLY_PREFIX_PATTERN = '\\(?\\$1\\)?';
     public static $PLUS_CHARS_PATTERN;
@@ -120,6 +120,7 @@ class PhoneNumberUtil
 
     /**
      * Only upper-case variants of alpha characters are stored.
+     *
      * @var array
      */
     protected static $ALPHA_MAPPINGS = array(
@@ -155,6 +156,7 @@ class PhoneNumberUtil
      * Map of country calling codes that use a mobile token before the area code. One example of when
      * this is relevant is when determining the length of the national destination code, which should
      * be the length of the area code plus the length of the mobile token.
+     *
      * @var array
      */
     protected static $MOBILE_TOKEN_MAPPINGS = array();
@@ -182,6 +184,7 @@ class PhoneNumberUtil
 
     /**
      * For performance reasons, amalgamate both into one map.
+     *
      * @var array
      */
     protected static $ALPHA_PHONE_MAPPINGS;
@@ -189,6 +192,7 @@ class PhoneNumberUtil
     /**
      * Separate map of all symbols that we wish to retain when formatting alpha numbers. This
      * includes digits, ASCII letters and number grouping symbols such as "-" and " ".
+     *
      * @var array
      */
     protected static $ALL_PLUS_NUMBER_GROUPING_SYMBOLS;
@@ -196,6 +200,7 @@ class PhoneNumberUtil
     /**
      * Simple ASCII digits map used to populate ALPHA_PHONE_MAPPINGS and
      * ALL_PLUS_NUMBER_GROUPING_SYMBOLS.
+     *
      * @var array
      */
     protected static $asciiDigitMappings = array(
@@ -215,11 +220,13 @@ class PhoneNumberUtil
      * Regexp of all possible ways to write extensions, for use when parsing. This will be run as a
      * case-insensitive regexp match. Wide character versions are also provided after each ASCII
      * version.
+     *
      * @var String
      */
     protected static $EXTN_PATTERNS_FOR_PARSING;
     /**
      * @var string
+     *
      * @internal
      */
     public static $EXTN_PATTERNS_FOR_MATCHING;
@@ -243,6 +250,7 @@ class PhoneNumberUtil
      * have alpha-characters and punctuation.
      *
      * Note VALID_PUNCTUATION starts with a -, so must be the first in the range.
+     *
      * @var string
      */
     protected static $VALID_PHONE_NUMBER;
@@ -294,11 +302,13 @@ class PhoneNumberUtil
 
     /**
      * The set of county calling codes that map to the non-geo entity region ("001").
+     *
      * @var array
      */
     protected $countryCodesForNonGeographicalRegion = array();
     /**
      * The set of regions the library supports.
+     *
      * @var array
      */
     protected $supportedRegions = array();
@@ -308,11 +318,13 @@ class PhoneNumberUtil
      * by that country calling code. In the case of multiple regions sharing a calling code, such as
      * the NANPA regions, the one indicated with "isMainCountryForCode" in the metadata should be
      * first.
+     *
      * @var array
      */
     protected $countryCallingCodeToRegionCodeMap = array();
     /**
      * The set of regions that share country calling code 1.
+     *
      * @var array
      */
     protected $nanpaRegions = array();
@@ -393,10 +405,10 @@ protected function __construct(MetadataSourceInterface $metadataSource, $country
 
     /**
      * Gets a {@link PhoneNumberUtil} instance to carry out international phone number formatting,
-     * parsing, or validation. The instance is loaded with phone number metadata for a number of most
+     * parsing or validation. The instance is loaded with phone number metadata for a number of most
      * commonly used regions.
      *
-     * <p>The {@link PhoneNumberUtil} is implemented as a singleton. Therefore, calling getInstance
+     * <p>The {@link PhoneNumberUtil} is implemented as a singleton. Therefore calling getInstance
      * multiple times will only result in one instance being created.
      *
      * @param string $baseFileLocation
@@ -481,6 +493,7 @@ public static function initExtnPatterns()
     /**
      * Helper initialiser method to create the regular-expression pattern to match extensions,
      * allowing the one-char extension symbols provided by {@code singleExtnSymbols}.
+     *
      * @param string $singleExtnSymbols
      * @return string
      */
@@ -552,6 +565,7 @@ public static function resetInstance()
     /**
      * Converts all alpha characters in a number to their respective digits on a keypad, but retains
      * existing formatting.
+     *
      * @param string $number
      * @return string
      */
@@ -571,10 +585,10 @@ public static function convertAlphaCharactersInNumber($number)
      *
      * @param string $number a string of characters representing a phone number
      * @param array $normalizationReplacements a mapping of characters to what they should be replaced by in
-     * the normalized version of the phone number
-     * @param bool $removeNonMatches indicates whether characters that are not able to be replaced
+     * the normalized version of the phone number.
+     * @param bool $removeNonMatches indicates whether characters that are not able to be replaced.
      * should be stripped from the number. If this is false, they will be left unchanged in the number.
-     * @return string the normalized string version of the phone number
+     * @return string the normalized string version of the phone number.
      */
     protected static function normalizeHelper($number, array $normalizationReplacements, $removeNonMatches)
     {
@@ -595,6 +609,7 @@ protected static function normalizeHelper($number, array $normalizationReplaceme
     /**
      * Helper function to check if the national prefix formatting rule has the first group only, i.e.,
      * does not start with the national prefix.
+     *
      * @param string $nationalPrefixFormattingRule
      * @return bool
      */
@@ -677,7 +692,7 @@ protected static function descHasData(PhoneNumberDesc $desc)
     }
 
     /**
-     * Returns the types we have metadata for based on the PhoneMetadata object passed in
+     * Returns the types we have metadata for based on the PhoneMetadata object passed in.
      *
      * @param PhoneMetadata $metadata
      * @return array
@@ -773,6 +788,7 @@ public function getSupportedTypesForNonGeoEntity($countryCallingCode)
      *    entities
      *  <li> some geographical numbers have no area codes.
      * </ul>
+     *
      * @param PhoneNumber $number PhoneNumber object for which clients want to know the length of the area code.
      * @return int the length of area code of the PhoneNumber object passed in.
      */
@@ -810,6 +826,7 @@ public function getLengthOfGeographicalAreaCode(PhoneNumber $number)
     /**
      * Returns the metadata for the given region code or {@code null} if the region code is invalid
      * or unknown.
+     *
      * @param string $regionCode
      * @return null|PhoneMetadata
      */
@@ -824,6 +841,7 @@ public function getMetadataForRegion($regionCode)
 
     /**
      * Helper function to check region code is not unknown or null.
+     *
      * @param string $regionCode
      * @return bool
      */
@@ -856,6 +874,8 @@ public function getRegionCodeForNumber(PhoneNumber $number)
     }
 
     /**
+     * Returns the region code for a number from the list of region codes passing in.
+     *
      * @param PhoneNumber $number
      * @param array $regionCodes
      * @return null|string
@@ -904,6 +924,8 @@ public function getNationalSignificantNumber(PhoneNumber $number)
     }
 
     /**
+     * Returns the type of number passed in i.e Toll free, premium.
+     *
      * @param string $nationalNumber
      * @param PhoneMetadata $metadata
      * @return int PhoneNumberType constant
@@ -1012,6 +1034,7 @@ public function isNumberGeographical($phoneNumberObjOrType, $countryCallingCode
 
     /**
      * Gets the type of a valid phone number.
+     *
      * @param PhoneNumber $number the number the phone number that we want to know the type
      * @return int PhoneNumberType the type of the phone number, or UNKNOWN if it is invalid
      */
@@ -2188,7 +2211,7 @@ public function maybeStripNationalPrefixAndCarrierCode(&$number, PhoneMetadata $
 
     /**
      * Convenience wrapper around isPossibleNumberForTypeWithReason. Instead of returning the reason
-     * reason for failure, this method returns true if the number is either a possible fully-qualified
+     * for failure, this method returns true if the number is either a possible fully-qualified
      * number (containing the area code and country code), or if the number could be a possible local
      * number (with a country code, but missing an area code). Local numbers are considered possible
      * if they could be possibly dialled in this format: if the area code is needed for a call to
@@ -2751,7 +2774,7 @@ public function isNANPACountry($regionCode)
      * The original format is embedded in the country_code_source field of the PhoneNumber object
      * passed in. If such information is missing, the number will be formatted into the NATIONAL
      * format by default. When we don't have a formatting pattern for the number, the method returns
-     * the raw inptu when it is available.
+     * the raw input when it is available.
      *
      * Note this method guarantees no digit will be inserted, removed or modified as a result of
      * formatting.
@@ -3051,7 +3074,7 @@ public function formatByPattern(PhoneNumber $number, $numberFormat, array $userD
         // share a country calling code is contained by only one region for performance reasons. For
         // example, for NANPA regions it will be contained in the metadata for US.
         $regionCode = $this->getRegionCodeForCountryCode($countryCallingCode);
-        // Metadata cannot be null because the country calling code is valid
+        // Metadata cannot be null because the country calling code is valid.
         $metadata = $this->getMetadataForRegionOrCallingCode($countryCallingCode, $regionCode);
 
         $formattedNumber = '';
@@ -3186,7 +3209,7 @@ public function getExampleNumberForType($regionCodeOrType, $type = null)
                 }
             }
 
-            // If there wasn't an example number for a region, try the non-geographical entities
+            // If there wasn't an example number for a region, try the non-geographical entities.
             foreach ($this->getSupportedGlobalNetworkCallingCodes() as $countryCallingCode) {
                 $desc = $this->getNumberDescByType($this->getMetadataForNonGeographicalRegion($countryCallingCode), $regionCodeOrType);
                 try {
@@ -3433,6 +3456,13 @@ protected function isNationalNumberSuffixOfTheOther(PhoneNumber $firstNumber, Ph
         $this->stringEndsWithString($secondNumberNationalNumber, $firstNumberNationalNumber);
     }
 
+    /**
+     * Returns true if a string ends with a given substring, false otherwise.
+     *
+     * @param string $hayStack
+     * @param string $needle
+     * @return bool
+     */
     protected function stringEndsWithString($hayStack, $needle)
     {
         $revNeedle = strrev($needle);
@@ -3465,7 +3495,7 @@ public function isMobileNumberPortableRegion($regionCode)
      *
      * Convenience wrapper around {@link #isPossibleNumberWithReason}. Instead of returning the reason
      * for failure, this method returns a boolean value.
-     * for failure, this method returns true if the number is either a possible fully-qualified number
+     * For failure, this method returns true if the number is either a possible fully-qualified number
      * (containing the area code and country code), or if the number could be a possible local number
      * (with a country code, but missing an area code). Local numbers are considered possible if they
      * could be possibly dialled in this format: if the area code is needed for a call to connect, the
@@ -3580,6 +3610,7 @@ public function isPossibleNumberForTypeWithReason(PhoneNumber $number, $type)
      * Attempts to extract a valid number from a phone number that is too long to be valid, and resets
      * the PhoneNumber object passed in to that valid version. If no valid number could be extracted,
      * the PhoneNumber object passed in will not be modified.
+     *
      * @param PhoneNumber $number a PhoneNumber object which contains a number that is too long to be valid.
      * @return boolean true if a valid phone number can be successfully extracted.
      */