diff -ru typo3_src-4.0beta3.orig/t3lib/class.t3lib_tsparser.php typo3_src-4.0beta3/t3lib/class.t3lib_tsparser.php
--- typo3_src-4.0beta3.orig/t3lib/class.t3lib_tsparser.php	2006-01-31 12:19:50.000000000 +0100
+++ typo3_src-4.0beta3/t3lib/class.t3lib_tsparser.php	2006-02-03 12:32:58.000000000 +0100
@@ -216,7 +216,7 @@
 								$setup[$this->multiLineObject.'.ln..'][]=($this->lineNumberOffset+$this->rawP-1);
 							}
 						}
-					} else{
+					} else {
 						if ($this->syntaxHighLight)	$this->regHighLight("value",$lineP);
 						$this->multiLineValue[]=$this->raw[($this->rawP-1)];
 					}
@@ -246,9 +246,44 @@
 										$this->regHighLight("operator_postspace", $lineP, strlen(ltrim(substr($line,1))));
 									}
 								}
+
 								switch(substr($line,0,1))	{
 									case '=':
-										if ($this->syntaxHighLight)	$this->regHighLight("value", $lineP, strlen(ltrim(substr($line,1)))-strlen(trim(substr($line,1))));
+										if ($this->syntaxHighLight)	$this->regHighLight('value', $lineP, strlen(ltrim(substr($line,1)))-strlen(trim(substr($line,1))));
+
+											// Checking for TS-modify properties
+										if (preg_match('/.*\._[^\.]+/', $objStrName))	{
+											$operator = preg_replace('/.*\.(_[^\.]+)/', '$1', $objStrName);	// Examples: _addString, _removeFromList, etc.
+											$propertyName = str_replace('.'.$operator, '', $objStrName);	// Name of the parent property (which will be changed)
+											list ($currentValue) = $this->getVal($propertyName,$setup);
+											$operationValue = substr($line,1);	// Value to be added/removed from $currentValue
+
+											switch ($operator)	{
+												case '_addString':
+													$newValue = $currentValue . trim($operationValue);
+												break;
+												case '_removeString':
+													$newValue = str_replace(trim($operationValue), '', $currentValue);
+												break;
+												case '_addToList':
+													$newValue = (strcmp('',$currentValue) ? $currentValue.',' : '') . trim($operationValue);
+												break;
+												case '_removeFromList':
+													$existingElements = t3lib_div::trimExplode(',',$currentValue);
+													$removeElements = t3lib_div::trimExplode(',',$operationValue);
+													if (count($removeElements))	{
+														$newValue = implode(',', array_diff($existingElements, $removeElements));
+													}
+												break;
+											}
+
+											if (isset($newValue))	{
+												$this->setVal($propertyName,$setup,array($newValue));
+												unset($newValue);
+												continue;
+											}
+										}
+
 										if (strstr($objStrName,'.'))	{
 											$value = Array();
 											$value[0] = trim(substr($line,1));
@@ -523,7 +558,7 @@
 
 	/**
 	 * Syntax highlight a TypoScript text
-	 * Will parse the content. Remember, the internal setup array may contain INvalid parsed content since conditions are ignored!
+	 * Will parse the content. Remember, the internal setup array may contain invalid parsed content since conditions are ignored!
 	 *
 	 * @param	string		The TypoScript text
 	 * @param	mixed		If blank, linenumbers are NOT printed. If array then the first key is the linenumber offset to add to the internal counter.