diff --git a/lib/Sabberworm/CSS/CSSList/AtRuleBlockList.php b/lib/Sabberworm/CSS/CSSList/AtRuleBlockList.php
index 24e79f02..dbcc99c6 100644
--- a/lib/Sabberworm/CSS/CSSList/AtRuleBlockList.php
+++ b/lib/Sabberworm/CSS/CSSList/AtRuleBlockList.php
@@ -8,20 +8,37 @@
  * A BlockList constructed by an unknown @-rule. @media rules are rendered into AtRuleBlockList objects.
  */
 class AtRuleBlockList extends CSSBlockList implements AtRule {
-
+	/**
+	 * @var string
+	 */
 	private $sType;
+
+	/**
+	 * @var string
+	 */
 	private $sArgs;
 
+	/**
+	 * @param string $sType
+	 * @param string $sArgs
+	 * @param int $iLineNo
+	 */
 	public function __construct($sType, $sArgs = '', $iLineNo = 0) {
 		parent::__construct($iLineNo);
 		$this->sType = $sType;
 		$this->sArgs = $sArgs;
 	}
 
+	/**
+	 * @return string
+	 */
 	public function atRuleName() {
 		return $this->sType;
 	}
 
+	/**
+	 * @return string
+	 */
 	public function atRuleArgs() {
 		return $this->sArgs;
 	}
@@ -30,6 +47,9 @@ public function __toString() {
 		return $this->render(new \Sabberworm\CSS\OutputFormat());
 	}
 
+	/**
+	 * @return string
+	 */
 	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
 		$sArgs = $this->sArgs;
 		if($sArgs) {
diff --git a/lib/Sabberworm/CSS/CSSList/CSSList.php b/lib/Sabberworm/CSS/CSSList/CSSList.php
index 74336383..a58fda50 100644
--- a/lib/Sabberworm/CSS/CSSList/CSSList.php
+++ b/lib/Sabberworm/CSS/CSSList/CSSList.php
@@ -25,11 +25,24 @@
  * Also, it may contain Import and Charset objects stemming from @-rules.
  */
 abstract class CSSList implements Renderable, Commentable {
-
+	/**
+	 * @var array
+	 */
 	protected $aComments;
+
+	/**
+	 * @var array<int, RuleSet|Import|Charset|CSSList>
+	 */
 	protected $aContents;
+
+	/**
+	 * @var int
+	 */
 	protected $iLineNo;
 
+	/**
+	 * @param int $iLineNo
+	 */
 	public function __construct($iLineNo = 0) {
 		$this->aComments = array();
 		$this->aContents = array();
@@ -195,7 +208,7 @@ public function getLineNo() {
 	/**
 	 * Prepend item to list of contents.
 	 *
-	 * @param object $oItem Item.
+	 * @param RuleSet|Import|Charset|CSSList $oItem Item.
 	 */
 	public function prepend($oItem) {
 		array_unshift($this->aContents, $oItem);
@@ -204,7 +217,7 @@ public function prepend($oItem) {
 	/**
 	 * Append item to list of contents.
 	 *
-	 * @param object $oItem Item.
+	 * @param RuleSet|Import|Charset|CSSList $oItem Item.
 	 */
 	public function append($oItem) {
 		$this->aContents[] = $oItem;
@@ -237,6 +250,7 @@ public function remove($oItemToRemove) {
 
 	/**
 	 * Replaces an item from the CSS list.
+	 *
 	 * @param RuleSet|Import|Charset|CSSList $oItemToRemove May be a RuleSet (most likely a DeclarationBlock), a Import, a Charset or another CSSList (most likely a MediaQuery)
 	 */
 	public function replace($oOldItem, $mNewItem) {
@@ -254,7 +268,7 @@ public function replace($oOldItem, $mNewItem) {
 
 	/**
 	 * Set the contents.
-	 * @param array $aContents Objects to set as content.
+	 * @param array<int, RuleSet|Import|Charset|CSSList> $aContents Objects to set as content.
 	 */
 	public function setContents(array $aContents) {
 		$this->aContents = array();
@@ -300,6 +314,9 @@ public function __toString() {
 		return $this->render(new \Sabberworm\CSS\OutputFormat());
 	}
 
+	/**
+	 * @return string
+	 */
 	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
 		$sResult = '';
 		$bIsFirst = true;
@@ -330,12 +347,15 @@ public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
 
 		return $sResult;
 	}
-	
+
 	/**
 	* Return true if the list can not be further outdented. Only important when rendering.
 	*/
 	public abstract function isRootList();
 
+	/**
+	 * @return array<int, RuleSet|Import|Charset|CSSList>
+	 */
 	public function getContents() {
 		return $this->aContents;
 	}
diff --git a/lib/Sabberworm/CSS/CSSList/Document.php b/lib/Sabberworm/CSS/CSSList/Document.php
index 1658aee8..8abcb358 100644
--- a/lib/Sabberworm/CSS/CSSList/Document.php
+++ b/lib/Sabberworm/CSS/CSSList/Document.php
@@ -16,6 +16,13 @@ public function __construct($iLineNo = 0) {
 		parent::__construct($iLineNo);
 	}
 
+	/**
+	 * @param ParserState $oParserState
+	 *
+	 * @return Document
+	 *
+	 * @throws \Sabberworm\CSS\Parsing\SourceException
+	 */
 	public static function parse(ParserState $oParserState) {
 		$oDocument = new Document($oParserState->currentLine());
 		CSSList::parseList($oParserState, $oDocument);
@@ -95,7 +102,14 @@ public function createShorthands() {
 		}
 	}
 
-	// Override render() to make format argument optional
+
+	/**
+	 * Override render() to make format argument optional
+	 *
+	 * @param \Sabberworm\CSS\OutputFormat|null $oOutputFormat
+	 *
+	 * @return string
+	 */
 	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat = null) {
 		if($oOutputFormat === null) {
 			$oOutputFormat = new \Sabberworm\CSS\OutputFormat();
diff --git a/lib/Sabberworm/CSS/CSSList/KeyFrame.php b/lib/Sabberworm/CSS/CSSList/KeyFrame.php
index 0334b1b3..d788be98 100644
--- a/lib/Sabberworm/CSS/CSSList/KeyFrame.php
+++ b/lib/Sabberworm/CSS/CSSList/KeyFrame.php
@@ -5,8 +5,14 @@
 use Sabberworm\CSS\Property\AtRule;
 
 class KeyFrame extends CSSList implements AtRule {
-
+	/**
+	 * @var string|null
+	 */
 	private $vendorKeyFrame;
+
+	/**
+	 * @var string|null
+	 */
 	private $animationName;
 
 	public function __construct($iLineNo = 0) {
@@ -35,6 +41,11 @@ public function __toString() {
 		return $this->render(new \Sabberworm\CSS\OutputFormat());
 	}
 
+	/**
+	 * @param \Sabberworm\CSS\OutputFormat $oOutputFormat
+	 *
+	 * @return string
+	 */
 	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
 		$sResult = "@{$this->vendorKeyFrame} {$this->animationName}{$oOutputFormat->spaceBeforeOpeningBrace()}{";
 		$sResult .= parent::render($oOutputFormat);
@@ -46,10 +57,16 @@ public function isRootList() {
 		return false;
 	}
 
+	/**
+	 * @return string|null
+	 */
 	public function atRuleName() {
 		return $this->vendorKeyFrame;
 	}
 
+	/**
+	 * @return string|null
+	 */
 	public function atRuleArgs() {
 		return $this->animationName;
 	}
diff --git a/lib/Sabberworm/CSS/Parser.php b/lib/Sabberworm/CSS/Parser.php
index 2520cb34..7714a31e 100644
--- a/lib/Sabberworm/CSS/Parser.php
+++ b/lib/Sabberworm/CSS/Parser.php
@@ -9,6 +9,9 @@
  * Parser class parses CSS from text into a data structure.
  */
 class Parser {
+	/**
+	 * @var ParserState
+	 */
 	private $oParserState;
 
 	/**
@@ -34,8 +37,12 @@ public function getCharset() {
 		$this->oParserState->getCharset();
 	}
 
+	/**
+	 * @return Document
+	 *
+	 * @throws Parsing\SourceException
+	 */
 	public function parse() {
 		return Document::parse($this->oParserState);
 	}
-
 }
diff --git a/lib/Sabberworm/CSS/Property/AtRule.php b/lib/Sabberworm/CSS/Property/AtRule.php
index b20c8c6e..aaeadb33 100644
--- a/lib/Sabberworm/CSS/Property/AtRule.php
+++ b/lib/Sabberworm/CSS/Property/AtRule.php
@@ -10,7 +10,14 @@ interface AtRule extends Renderable, Commentable {
 	const BLOCK_RULES = 'media/document/supports/region-style/font-feature-values';
 	// …and more font-specific ones (to be used inside font-feature-values)
 	const SET_RULES = 'font-face/counter-style/page/swash/styleset/annotation';
-	
+
+	/**
+	 * @return string|null
+	 */
 	public function atRuleName();
+
+	/**
+	 * @return string|null
+	 */
 	public function atRuleArgs();
 }
\ No newline at end of file
diff --git a/lib/Sabberworm/CSS/Property/CSSNamespace.php b/lib/Sabberworm/CSS/Property/CSSNamespace.php
index 7c0dee15..cf75de2e 100644
--- a/lib/Sabberworm/CSS/Property/CSSNamespace.php
+++ b/lib/Sabberworm/CSS/Property/CSSNamespace.php
@@ -10,7 +10,7 @@ class CSSNamespace implements AtRule {
 	private $sPrefix;
 	private $iLineNo;
 	protected $aComments;
-	
+
 	public function __construct($mUrl, $sPrefix = null, $iLineNo = 0) {
 		$this->mUrl = $mUrl;
 		$this->sPrefix = $sPrefix;
@@ -29,10 +29,15 @@ public function __toString() {
 		return $this->render(new \Sabberworm\CSS\OutputFormat());
 	}
 
+	/**
+	 * @param \Sabberworm\CSS\OutputFormat $oOutputFormat
+	 *
+	 * @return string
+	 */
 	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
 		return '@namespace '.($this->sPrefix === null ? '' : $this->sPrefix.' ').$this->mUrl->render($oOutputFormat).';';
 	}
-	
+
 	public function getUrl() {
 		return $this->mUrl;
 	}
@@ -49,10 +54,16 @@ public function setPrefix($sPrefix) {
 		$this->sPrefix = $sPrefix;
 	}
 
+	/**
+	 * @return string
+	 */
 	public function atRuleName() {
 		return 'namespace';
 	}
 
+	/**
+	 * @return array<int, string>
+	 */
 	public function atRuleArgs() {
 		$aResult = array($this->mUrl);
 		if($this->sPrefix) {
diff --git a/lib/Sabberworm/CSS/Property/Charset.php b/lib/Sabberworm/CSS/Property/Charset.php
index 61c6ebc5..65dabc8a 100644
--- a/lib/Sabberworm/CSS/Property/Charset.php
+++ b/lib/Sabberworm/CSS/Property/Charset.php
@@ -10,11 +10,25 @@
  * • Must not appear more than once.
  */
 class Charset implements AtRule {
-
+	/**
+	 * @var string
+	 */
 	private $sCharset;
+
+	/**
+	 * @var int
+	 */
 	protected $iLineNo;
+
+	/**
+	 * @var array
+	 */
 	protected $aComment;
 
+	/**
+	 * @param string $sCharset
+	 * @param int $iLineNo
+	 */
 	public function __construct($sCharset, $iLineNo = 0) {
 		$this->sCharset = $sCharset;
 		$this->iLineNo = $iLineNo;
@@ -40,14 +54,25 @@ public function __toString() {
 		return $this->render(new \Sabberworm\CSS\OutputFormat());
 	}
 
+	/**
+	 * @param \Sabberworm\CSS\OutputFormat $oOutputFormat
+	 *
+	 * @return string
+	 */
 	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
 		return "@charset {$this->sCharset->render($oOutputFormat)};";
 	}
 
+	/**
+	 * @return string
+	 */
 	public function atRuleName() {
 		return 'charset';
 	}
 
+	/**
+	 * @return string
+	 */
 	public function atRuleArgs() {
 		return $this->sCharset;
 	}
@@ -63,4 +88,4 @@ public function getComments() {
 	public function setComments(array $aComments) {
 		$this->aComments = $aComments;
 	}
-}
\ No newline at end of file
+}
diff --git a/lib/Sabberworm/CSS/Property/Import.php b/lib/Sabberworm/CSS/Property/Import.php
index 4d40f5a0..162ba206 100644
--- a/lib/Sabberworm/CSS/Property/Import.php
+++ b/lib/Sabberworm/CSS/Property/Import.php
@@ -8,11 +8,31 @@
 * Class representing an @import rule.
 */
 class Import implements AtRule {
+	/**
+	 * @var URL
+	 */
 	private $oLocation;
+
+	/**
+	 * @var string
+	 */
 	private $sMediaQuery;
+
+	/**
+	 * @var int
+	 */
 	protected $iLineNo;
+
+	/**
+	 * @var array
+	 */
 	protected $aComments;
-	
+
+	/**
+	 * @param URL $oLocation
+	 * @param string $sMediaQuery
+	 * @param int $iLineNo
+	 */
 	public function __construct(URL $oLocation, $sMediaQuery, $iLineNo = 0) {
 		$this->oLocation = $oLocation;
 		$this->sMediaQuery = $sMediaQuery;
@@ -27,26 +47,37 @@ public function getLineNo() {
 		return $this->iLineNo;
 	}
 
-	public function setLocation($oLocation) {
+    public function setLocation($oLocation) {
 			$this->oLocation = $oLocation;
 	}
 
 	public function getLocation() {
 			return $this->oLocation;
 	}
-	
+
 	public function __toString() {
 		return $this->render(new \Sabberworm\CSS\OutputFormat());
 	}
 
+	/**
+	 * @param \Sabberworm\CSS\OutputFormat $oOutputFormat
+	 *
+	 * @return string
+	 */
 	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
 		return "@import ".$this->oLocation->render($oOutputFormat).($this->sMediaQuery === null ? '' : ' '.$this->sMediaQuery).';';
 	}
 
+	/**
+	 * @return string
+	 */
 	public function atRuleName() {
 		return 'import';
 	}
 
+	/**
+	 * @return array<int, URL|string>
+	 */
 	public function atRuleArgs() {
 		$aResult = array($this->oLocation);
 		if($this->sMediaQuery) {
diff --git a/lib/Sabberworm/CSS/Renderable.php b/lib/Sabberworm/CSS/Renderable.php
index 3ac06652..862580c5 100644
--- a/lib/Sabberworm/CSS/Renderable.php
+++ b/lib/Sabberworm/CSS/Renderable.php
@@ -4,6 +4,13 @@
 
 interface Renderable {
 	public function __toString();
+
+	/**
+	 * @param OutputFormat $oOutputFormat
+	 *
+	 * @return string
+	 */
 	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat);
+
 	public function getLineNo();
 }
\ No newline at end of file
diff --git a/lib/Sabberworm/CSS/Rule/Rule.php b/lib/Sabberworm/CSS/Rule/Rule.php
index 306bd35d..55f89c11 100644
--- a/lib/Sabberworm/CSS/Rule/Rule.php
+++ b/lib/Sabberworm/CSS/Rule/Rule.php
@@ -209,6 +209,11 @@ public function __toString() {
 		return $this->render(new \Sabberworm\CSS\OutputFormat());
 	}
 
+	/**
+	 * @param \Sabberworm\CSS\OutputFormat $oOutputFormat
+	 *
+	 * @return string
+	 */
 	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
 		$sResult = "{$this->sRule}:{$oOutputFormat->spaceAfterRuleName()}";
 		if ($this->mValue instanceof Value) { //Can also be a ValueList
diff --git a/lib/Sabberworm/CSS/RuleSet/AtRuleSet.php b/lib/Sabberworm/CSS/RuleSet/AtRuleSet.php
index a1042a95..9b892ae3 100644
--- a/lib/Sabberworm/CSS/RuleSet/AtRuleSet.php
+++ b/lib/Sabberworm/CSS/RuleSet/AtRuleSet.php
@@ -8,20 +8,37 @@
  * A RuleSet constructed by an unknown @-rule. @font-face rules are rendered into AtRuleSet objects.
  */
 class AtRuleSet extends RuleSet implements AtRule {
-
+	/**
+	 * @var string
+	 */
 	private $sType;
+
+	/**
+	 * @var string
+	 */
 	private $sArgs;
 
+	/**
+	 * @param string $sType
+	 * @param string $sArgs
+	 * @param int $iLineNo
+	 */
 	public function __construct($sType, $sArgs = '', $iLineNo = 0) {
 		parent::__construct($iLineNo);
 		$this->sType = $sType;
 		$this->sArgs = $sArgs;
 	}
 
+	/**
+	 * @return string
+	 */
 	public function atRuleName() {
 		return $this->sType;
 	}
 
+	/**
+	 * @return string
+	 */
 	public function atRuleArgs() {
 		return $this->sArgs;
 	}
@@ -30,6 +47,11 @@ public function __toString() {
 		return $this->render(new \Sabberworm\CSS\OutputFormat());
 	}
 
+	/**
+	 * @param \Sabberworm\CSS\OutputFormat $oOutputFormat
+	 *
+	 * @return string
+	 */
 	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
 		$sArgs = $this->sArgs;
 		if($sArgs) {
diff --git a/lib/Sabberworm/CSS/RuleSet/DeclarationBlock.php b/lib/Sabberworm/CSS/RuleSet/DeclarationBlock.php
index 20fab0d9..c3bcdd07 100644
--- a/lib/Sabberworm/CSS/RuleSet/DeclarationBlock.php
+++ b/lib/Sabberworm/CSS/RuleSet/DeclarationBlock.php
@@ -20,7 +20,9 @@
  * Declaration blocks usually appear directly inside a Document or another CSSList (mostly a MediaQuery).
  */
 class DeclarationBlock extends RuleSet {
-
+	/**
+	 * @var array<int, Selector>
+	 */
 	private $aSelectors;
 
 	public function __construct($iLineNo = 0) {
@@ -118,7 +120,7 @@ public function setSelector($mSelector, $oList = NULL) {
 	/**
 	 * Get selectors.
 	 *
-	 * @return Selector[] Selectors.
+	 * @return array<int, Selector> Selectors.
 	 */
 	public function getSelectors() {
 		return $this->aSelectors;
@@ -142,7 +144,7 @@ public function expandShorthands() {
 	public function createShorthands() {
 		$this->createBackgroundShorthand();
 		$this->createDimensionsShorthand();
-		// border must be shortened after dimensions 
+		// border must be shortened after dimensions
 		$this->createBorderShorthand();
 		$this->createFontShorthand();
 		$this->createListStyleShorthand();
@@ -501,7 +503,7 @@ public function createBorderShorthand() {
 
 	/*
 	 * Looks for long format CSS dimensional properties
-	 * (margin, padding, border-color, border-style and border-width) 
+	 * (margin, padding, border-color, border-style and border-width)
 	 * and converts them into shorthand CSS properties.
 	 * */
 
@@ -556,7 +558,7 @@ public function createDimensionsShorthand() {
 						$oNewRule->addValue($aValues['bottom']);
 					}
 				} else {
-					// No sides are equal 
+					// No sides are equal
 					$oNewRule->addValue($aValues['top']);
 					$oNewRule->addValue($aValues['left']);
 					$oNewRule->addValue($aValues['bottom']);
@@ -571,8 +573,8 @@ public function createDimensionsShorthand() {
 	}
 
 	/**
-	 * Looks for long format CSS font properties (e.g. <tt>font-weight</tt>) and 
-	 * tries to convert them into a shorthand CSS <tt>font</tt> property. 
+	 * Looks for long format CSS font properties (e.g. <tt>font-weight</tt>) and
+	 * tries to convert them into a shorthand CSS <tt>font</tt> property.
 	 * At least font-size AND font-family must be present in order to create a shorthand declaration.
 	 * */
 	public function createFontShorthand() {
@@ -651,6 +653,13 @@ public function __toString() {
 		return $this->render(new \Sabberworm\CSS\OutputFormat());
 	}
 
+	/**
+	 * @param \Sabberworm\CSS\OutputFormat $oOutputFormat
+	 *
+	 * @return string
+	 *
+	 * @throws OutputException
+	 */
 	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
 		if(count($this->aSelectors) === 0) {
 			// If all the selectors have been removed, this declaration block becomes invalid
diff --git a/lib/Sabberworm/CSS/RuleSet/RuleSet.php b/lib/Sabberworm/CSS/RuleSet/RuleSet.php
index f63a3f16..79bfcd04 100644
--- a/lib/Sabberworm/CSS/RuleSet/RuleSet.php
+++ b/lib/Sabberworm/CSS/RuleSet/RuleSet.php
@@ -96,10 +96,13 @@ public function addRule(Rule $oRule, Rule $oSibling = null) {
 
 	/**
 	 * Returns all rules matching the given rule name
-	 * @param (null|string|Rule) $mRule pattern to search for. If null, returns all rules. if the pattern ends with a dash, all rules starting with the pattern are returned as well as one matching the pattern with the dash excluded. passing a Rule behaves like calling getRules($mRule->getRule()).
+	 *
+	 * @param null|string|Rule $mRule pattern to search for. If null, returns all rules. if the pattern ends with a dash, all rules starting with the pattern are returned as well as one matching the pattern with the dash excluded. passing a Rule behaves like calling getRules($mRule->getRule()).
+	 *
 	 * @example $oRuleSet->getRules('font-') //returns an array of all rules either beginning with font- or matching font.
 	 * @example $oRuleSet->getRules('font') //returns array(0 => $oRule, …) or array().
-	 * @return Rule[] Rules.
+	 *
+	 * @return array<int, Rule> Rules.
 	 */
 	public function getRules($mRule = null) {
 		if ($mRule instanceof Rule) {
@@ -175,6 +178,11 @@ public function __toString() {
 		return $this->render(new \Sabberworm\CSS\OutputFormat());
 	}
 
+	/**
+	 * @param \Sabberworm\CSS\OutputFormat $oOutputFormat
+	 *
+	 * @return string
+	 */
 	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
 		$sResult = '';
 		$bIsFirst = true;
@@ -195,7 +203,7 @@ public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
 				$sResult .= $sRendered;
 			}
 		}
-		
+
 		if(!$bIsFirst) {
 			// Had some output
 			$sResult .= $oOutputFormat->spaceAfterRules();
diff --git a/lib/Sabberworm/CSS/Value/CSSFunction.php b/lib/Sabberworm/CSS/Value/CSSFunction.php
index 941df236..28775505 100644
--- a/lib/Sabberworm/CSS/Value/CSSFunction.php
+++ b/lib/Sabberworm/CSS/Value/CSSFunction.php
@@ -32,6 +32,11 @@ public function __toString() {
 		return $this->render(new \Sabberworm\CSS\OutputFormat());
 	}
 
+	/**
+	 * @param \Sabberworm\CSS\OutputFormat $oOutputFormat
+	 *
+	 * @return string
+	 */
 	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
 		$aArguments = parent::render($oOutputFormat);
 		return "{$this->sName}({$aArguments})";
diff --git a/lib/Sabberworm/CSS/Value/CSSString.php b/lib/Sabberworm/CSS/Value/CSSString.php
index 9f9c050e..8ab5b7d8 100644
--- a/lib/Sabberworm/CSS/Value/CSSString.php
+++ b/lib/Sabberworm/CSS/Value/CSSString.php
@@ -57,6 +57,11 @@ public function __toString() {
 		return $this->render(new \Sabberworm\CSS\OutputFormat());
 	}
 
+	/**
+	 * @param \Sabberworm\CSS\OutputFormat $oOutputFormat
+	 *
+	 * @return string
+	 */
 	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
 		$sString = addslashes($this->sString);
 		$sString = str_replace("\n", '\A', $sString);
diff --git a/lib/Sabberworm/CSS/Value/CalcRuleValueList.php b/lib/Sabberworm/CSS/Value/CalcRuleValueList.php
index bde8a9d3..512ee546 100644
--- a/lib/Sabberworm/CSS/Value/CalcRuleValueList.php
+++ b/lib/Sabberworm/CSS/Value/CalcRuleValueList.php
@@ -7,6 +7,11 @@ public function __construct($iLineNo = 0) {
 		parent::__construct(array(), ',', $iLineNo);
 	}
 
+	/**
+	 * @param \Sabberworm\CSS\OutputFormat $oOutputFormat
+	 *
+	 * @return string
+	 */
 	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
 		return $oOutputFormat->implode(' ', $this->aComponents);
 	}
diff --git a/lib/Sabberworm/CSS/Value/Color.php b/lib/Sabberworm/CSS/Value/Color.php
index 5ff44699..0c21665c 100644
--- a/lib/Sabberworm/CSS/Value/Color.php
+++ b/lib/Sabberworm/CSS/Value/Color.php
@@ -96,6 +96,11 @@ public function __toString() {
 		return $this->render(new \Sabberworm\CSS\OutputFormat());
 	}
 
+	/**
+	 * @param \Sabberworm\CSS\OutputFormat $oOutputFormat
+	 *
+	 * @return string
+	 */
 	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
 		// Shorthand RGB color values
 		if($oOutputFormat->getRGBHashNotation() && implode('', array_keys($this->aComponents)) === 'rgb') {
diff --git a/lib/Sabberworm/CSS/Value/LineName.php b/lib/Sabberworm/CSS/Value/LineName.php
index 5376a9be..677e80e8 100644
--- a/lib/Sabberworm/CSS/Value/LineName.php
+++ b/lib/Sabberworm/CSS/Value/LineName.php
@@ -36,6 +36,11 @@ public function __toString() {
 		return $this->render(new \Sabberworm\CSS\OutputFormat());
 	}
 
+	/**
+	 * @param \Sabberworm\CSS\OutputFormat $oOutputFormat
+	 *
+	 * @return string
+	 */
 	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
 		return '[' . parent::render(\Sabberworm\CSS\OutputFormat::createCompact()) . ']';
 	}
diff --git a/lib/Sabberworm/CSS/Value/Size.php b/lib/Sabberworm/CSS/Value/Size.php
index 8490cc35..730f2dd4 100644
--- a/lib/Sabberworm/CSS/Value/Size.php
+++ b/lib/Sabberworm/CSS/Value/Size.php
@@ -112,6 +112,11 @@ public function __toString() {
 		return $this->render(new \Sabberworm\CSS\OutputFormat());
 	}
 
+	/**
+	 * @param \Sabberworm\CSS\OutputFormat $oOutputFormat
+	 *
+	 * @return string
+	 */
 	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
 		$l = localeconv();
 		$sPoint = preg_quote($l['decimal_point'], '/');
diff --git a/lib/Sabberworm/CSS/Value/URL.php b/lib/Sabberworm/CSS/Value/URL.php
index b4f37e16..00a741ee 100644
--- a/lib/Sabberworm/CSS/Value/URL.php
+++ b/lib/Sabberworm/CSS/Value/URL.php
@@ -42,6 +42,11 @@ public function __toString() {
 		return $this->render(new \Sabberworm\CSS\OutputFormat());
 	}
 
+	/**
+	 * @param \Sabberworm\CSS\OutputFormat $oOutputFormat
+	 *
+	 * @return string
+	 */
 	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
 		return "url({$this->oURL->render($oOutputFormat)})";
 	}
diff --git a/lib/Sabberworm/CSS/Value/ValueList.php b/lib/Sabberworm/CSS/Value/ValueList.php
index 5c3d0e4f..5bfc0ba9 100644
--- a/lib/Sabberworm/CSS/Value/ValueList.php
+++ b/lib/Sabberworm/CSS/Value/ValueList.php
@@ -40,6 +40,11 @@ public function __toString() {
 		return $this->render(new \Sabberworm\CSS\OutputFormat());
 	}
 
+	/**
+	 * @param \Sabberworm\CSS\OutputFormat $oOutputFormat
+	 *
+	 * @return string
+	 */
 	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
 		return $oOutputFormat->implode($oOutputFormat->spaceBeforeListArgumentSeparator($this->sSeparator) . $this->sSeparator . $oOutputFormat->spaceAfterListArgumentSeparator($this->sSeparator), $this->aComponents);
 	}