diff --git a/core/htmlsanitizer.class.inc.php b/core/htmlsanitizer.class.inc.php
index 5bcae80eb..b2a7aa4c7 100644
--- a/core/htmlsanitizer.class.inc.php
+++ b/core/htmlsanitizer.class.inc.php
@@ -160,65 +160,53 @@ class HTMLDOMSanitizer extends HTMLSanitizer
 	 * @see https://www.itophub.io/wiki/page?id=2_6_0%3Aadmin%3Arich_text_limitations
 	 */
 	protected static $aTagsWhiteList = array(
-		'a' => array('href', 'name', 'style', 'target', 'title'),
-		'b' => array(),
-		'big' => array(),
-		'blockquote' => array('style'),
+		'html' => array(),
 		'body' => array(),
+		'a' => array('href', 'name', 'style', 'target', 'title'),
+		'p' => array('style'),
+		'blockquote' => array('style'),
 		'br' => array(),
-		'center' => array(),
-		'cite' => array(),
-		'code' => array('style', 'class'),
-		'del' => array(),
+		'span' => array('style'),
 		'div' => array('style'),
+		'b' => array(),
+		'i' => array(),
+		'u' => array(),
 		'em' => array(),
-		'fieldset' => array('style'),
-		'font' => array('face', 'color', 'style', 'size'),
+		'strong' => array(),
+		'img' => array('src', 'style', 'alt', 'title'),
+		'ul' => array('style'),
+		'ol' => array('style'),
+		'li' => array('style'),
 		'h1' => array('style'),
 		'h2' => array('style'),
 		'h3' => array('style'),
 		'h4' => array('style'),
-		'hr' => array('style'),
-		'html' => array(),
-		'i' => array(),
-		'img' => array('src', 'style', 'alt', 'title'),
-		'ins' => array(),
-		'kbd' => array(),
-		'legend' => array('style'),
-		'li' => array('style'),
 		'nav' => array('style'),
-		'ol' => array('style'),
-		'p' => array('style'),
-		'pre' => array(),
-		'q' => array(),
-		'samp' => array(),
-		's' => array(), // strikethrough
 		'section' => array('style'),
-		'small' => array(),
-		'span' => array('style'),
-		'strong' => array(),
+		'code' => array('style', 'class'),
 		'table' => array('style', 'width', 'summary', 'align', 'border', 'cellpadding', 'cellspacing'),
+		'thead' => array('style'),
 		'tbody' => array('style'),
+		'tr' => array('style', 'colspan', 'rowspan'),
 		'td' => array('style', 'colspan', 'rowspan'),
 		'th' => array('style', 'colspan', 'rowspan'),
-		'thead' => array('style'),
-		'tr' => array('style', 'colspan', 'rowspan'),
+		'fieldset' => array('style'),
+		'legend' => array('style'),
+		'font' => array('face', 'color', 'style', 'size'),
+		'big' => array(),
+		'small' => array(),
 		'tt' => array(),
-		'u' => array(),
-		'ul' => array('style'),
+		'kbd' => array(),
+		'samp' => array(),
 		'var' => array(),
-	);
-
-	protected static $aTagsContentRemovableList = array(
-		'applet',
-		'basefont',
-		'canvas',
-		'code',
-		'dialog',
-		'embed',
-		'object',
-		'script',
-		'style',
+		'del' => array(),
+		's' => array(), // strikethrough
+		'ins' => array(),
+		'cite' => array(),
+		'q' => array(),
+		'hr' => array('style'),
+		'pre' => array(),
+		'center' => array(),
 	);
 
 	protected static $aAttrsWhiteList = array(
@@ -314,108 +302,6 @@ class HTMLDOMSanitizer extends HTMLSanitizer
 	}
 	
 	protected function CleanNode(DOMNode $oElement)
-	{
-		$this->CleanNodeRemoveForbiddenTags($oElement);
-		$this->CleanNodeHandleImages($oElement);
-		$this->CleanNodeRemoveForbiddenAttributes($oElement);
-	}
-
-	protected function CleanNodeRemoveForbiddenTags(DOMNode $oElement)
-	{
-		if ($oElement->hasChildNodes())
-		{
-			$aValidatedNodes = array();
-			do
-			{
-				$bChildRemoved = false;
-
-				$aNodes = array();
-				foreach($oElement->childNodes as $oNode)
-				{
-					$aNodes[] = $oNode;
-				}
-
-				foreach($aNodes as $oNode)
-				{
-					if (($oNode instanceof DOMElement) && (!array_key_exists(strtolower($oNode->tagName), self::$aTagsWhiteList)))
-					{
-						$bChildRemoved = true;
-						$this->SmartRemoveChild($oElement, $oNode);
-					}
-					else if ($oNode instanceof DOMComment)
-					{
-						$oElement->removeChild($oNode);
-					}
-					else
-					{
-						//if the node is kept, we can recurse into it, bu we want to perform this only once (see the do/while above?)
-						$bAlreadyValidated = false;
-						/** @var \DOMNode $oValidatedNode */
-						foreach ($aValidatedNodes as $oValidatedNode)
-						{
-							if ($oValidatedNode->isSameNode($oNode))
-							{
-								$bAlreadyValidated = true;
-								break;
-							}
-						}
-						if (! $bAlreadyValidated)
-						{
-							$this->CleanNodeRemoveForbiddenTags($oNode);
-							$aValidatedNodes[] = $oNode;
-						}
-					}
-				}
-			} while ($bChildRemoved);
-		}
-	}
-
-	/**
-	 * Remove a node, but move its inner nodes in the parent.
-	 * Note: invalid/forbidden tags may be moved up, so they have to be checked again.
-	 *
-	 * @param \DOMNode $oParent
-	 * @param \DOMElement $oRemovable
-	 */
-	private function SmartRemoveChild(DOMNode $oParent, DOMElement $oRemovable)
-	{
-		if (!$oRemovable->hasChildNodes())
-		{
-			$oParent->removeChild($oRemovable);
-		}
-		else if (in_array(strtolower($oRemovable->tagName), self::$aTagsContentRemovableList))
-		{
-			$oParent->removeChild($oRemovable);
-		}
-		else
-		{
-			/** @var \DOMNode $oNode */
-			foreach ($oRemovable->childNodes as $oNode)
-			{
-				$oNode = $oNode->cloneNode(true);
-				$oParent->insertBefore($oNode, $oRemovable);
-			}
-
-			$oParent->removeChild($oRemovable);
-		}
-	}
-
-	protected function CleanNodeHandleImages(DOMNode $oElement)
-	{
-		if ($oElement->hasChildNodes())
-		{
-			foreach($oElement->childNodes as $oNode)
-			{
-				$this->CleanNodeHandleImages($oNode);
-				if (($oNode instanceof DOMElement) && (strtolower($oNode->tagName) == 'img'))
-				{
-					InlineImage::ProcessImageTag($oNode);
-				}
-			}
-		}
-	}
-
-	protected function CleanNodeRemoveForbiddenAttributes(DOMNode $oElement)
 	{
 		$aAttrToRemove = array();
 		// Gather the attributes to remove
@@ -455,12 +341,35 @@ class HTMLDOMSanitizer extends HTMLSanitizer
 				$oElement->removeAttribute($sName);
 			}
 		}
-
+		
 		if ($oElement->hasChildNodes())
 		{
+			$aChildElementsToRemove = array();
+			// Gather the child noes to remove
 			foreach($oElement->childNodes as $oNode)
 			{
-				$this->CleanNodeRemoveForbiddenAttributes($oNode);
+				if (($oNode instanceof DOMElement) && (!array_key_exists(strtolower($oNode->tagName), self::$aTagsWhiteList)))
+				{
+					$aChildElementsToRemove[] = $oNode;
+				}
+				else if ($oNode instanceof DOMComment)
+				{
+					$aChildElementsToRemove[] = $oNode;
+				}
+				else
+				{
+					// Recurse
+					$this->CleanNode($oNode);
+					if (($oNode instanceof DOMElement) && (strtolower($oNode->tagName) == 'img'))
+					{
+						InlineImage::ProcessImageTag($oNode);
+					}
+				}
+			}
+			// Now remove them
+			foreach($aChildElementsToRemove as $oDomElement)
+			{
+				$oElement->removeChild($oDomElement);
 			}
 		}
 	}
diff --git a/test/core/HTMLDOMSanitizerTest.php b/test/core/HTMLDOMSanitizerTest.php
index d20656494..004b1cc74 100644
--- a/test/core/HTMLDOMSanitizerTest.php
+++ b/test/core/HTMLDOMSanitizerTest.php
@@ -168,83 +168,6 @@ class HTMLDOMSanitizerTest extends ItopTestCase
 		return $aTestCaseArray;
 	}
 
-	/**
-	 * Test the fix for ticket N°2556
-	 *
-	 * @dataProvider PreserveBlackListedTagContentProvider
-	 *
-	 */
-	public function testDoSanitizePreserveBlackListedTagContent($html, $expected)
-	{
-		$oSanitizer = new HTMLDOMSanitizer();
-		$sSanitizedHtml = $oSanitizer->DoSanitize($html);
-
-		$this->assertEquals($expected, str_replace("\n", '', $sSanitizedHtml));
-	}
-
-	public function PreserveBlackListedTagContentProvider()
-	{
-		return array(
-			'basic' => array(
-				'html' => '<iframe>bar</iframe>',
-				'expected' => 'bar',
-			),
-			'basic with body' => array(
-				'html' => '<body><iframe>bar</iframe></body>',
-				'expected' => 'bar',
-			),
-			'basic with html and body tags' => array(
-				'html' => '<html><body lang="EN-GB" link="#0563C1" vlink="#954F72"><iframe>bar</iframe></body></html>',
-				'expected' => 'bar',
-			),
-			'basic with attributes' => array(
-				'html' => '<iframe baz="1">bar</iframe>',
-				'expected' => 'bar',
-			),
-			'basic with comment' => array(
-				'html' => '<iframe baz="1">bar<!-- foo --></iframe>',
-				'expected' => 'bar',
-			),
-			'basic with contentRemovable tag' => array(
-				'html' => '<iframe baz="1">bar<style>foo</style><script>boo</script></iframe>',
-				'expected' => 'bar',
-			),
-			'nested' => array(
-				'html' => '<iframe>foo<article>baz</article>oof<article><iframe>bar</iframe>oof</article></iframe>',
-				'expected' => 'foobazoofbaroof',
-			),
-			'nested with not closed br' => array(
-				'html' => '<iframe>foo<article>baz</article>oof<br><article><iframe>bar</iframe>oof</article></iframe>',
-				'expected' => 'foobazoof<br>baroof',
-			),
-			'nested with allowed' => array(
-				'html' => '<iframe><div><article><p>baz</p>zab</article></div>oof</iframe>',
-				'expected' => '<div><p>baz</p>zab</div>oof',
-			),
-			'nested with spaces' => array(
-				'html' => '<iframe><article>baz</article> oof</iframe>',
-				'expected' => 'baz oof',
-			),
-			'nested with attributes' => array(
-				'html' => '<iframe baz="1"><article baz="1" biz="2">baz</article>oof</iframe>',
-				'expected' => 'bazoof',
-			),
-			'nested with allowed and attributes and spaces ' => array(
-				'html' => '<html><body><iframe baz="1"><div baz="baz"><article baz="1" biz="2">baz</article>rab</div> oof</iframe></body></html>',
-				'expected' => '<div>bazrab</div> oof',
-			),
-			'nested with allowed and contentRemovable tags' => array(
-				'html' => '<html><body><iframe baz="1"><div ><article>baz</article>rab</div> oof<embed>embedTExt</embed></iframe><style>foo</style><script>boo</script></body></html>',
-				'expected' => '<div>bazrab</div> oof',
-			),
-
-			'regression: if head present => body is not trimmed' => array(
-				'html' => '<html><head></head><body lang="EN-GB" link="#0563C1" vlink="#954F72">bar</body></html>',
-				'expected' => 'bar',
-			),
-		);
-	}
-
 	/**
 	 * Generates an appropriate value for the given attribute, or use the counter if needed.
 	 * This is necessary as most of the attributes with empty or inappropriate values (like a numeric for a href) are removed by the parser
@@ -279,43 +202,5 @@ class HTMLDOMSanitizerTest extends ItopTestCase
 
 		return true;
 	}
-
-	/**
-	 * @dataProvider CallInlineImageProcessImageTagProvider
-	 */
-	public function testDoSanitizeCallInlineImageProcessImageTag($sHtml, $iExpectedCount)
-	{
-		require_once APPROOT.'test/core/sanitizer/InlineImageMock.php';
-
-		$oSanitizer = new HTMLDOMSanitizer();
-		$oSanitizer->DoSanitize($sHtml);
-
-		$iCalledCount = \InlineImage::GetCallCounter();
-		$this->assertEquals($iExpectedCount, $iCalledCount);
-	}
-
-	public function CallInlineImageProcessImageTagProvider()
-	{
-		return array(
-			'no image' => array(
-				'html' => '<p>bar</p>',
-				'expected' => 0,
-			),
-			'basic image' => array(
-				'html' => '<img />',
-				'expected' => 1,
-			),
-			'nested images within forbidden tags' => array(
-				'html' => '<html><body><img /><iframe baz="1"><div baz="baz"><article baz="1" biz="2">baz<img /><img /></article>rab</div> oof<img /></iframe><img /></body></html>',
-				'expected' => 5,
-			),
-			'nested images within forbidden and removed tags' => array(
-				'html' => '<html><body><img /><iframe baz="1"><div baz="baz"><object baz="1" biz="2">baz<img /><img /></object>rab</div> oof<img /></iframe><img /></body></html>',
-				'expected' => 3,
-			),
-		);
-	}
-
-
 }
 
diff --git a/test/core/sanitizer/InlineImageMock.php b/test/core/sanitizer/InlineImageMock.php
deleted file mode 100644
index d5ad33218..000000000
--- a/test/core/sanitizer/InlineImageMock.php
+++ /dev/null
@@ -1,39 +0,0 @@
-<?php
-/**
- * Copyright (C) 2010-2020 Combodo SARL
- *
- *   This file is part of iTop.
- *
- *   iTop is free software; you can redistribute it and/or modify
- *   it under the terms of the GNU Affero General Public License as published by
- *   the Free Software Foundation, either version 3 of the License, or
- *   (at your option) any later version.
- *
- *   iTop is distributed in the hope that it will be useful,
- *   but WITHOUT ANY WARRANTY; without even the implied warranty of
- *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *   GNU Affero General Public License for more details.
- *
- *   You should have received a copy of the GNU Affero General Public License
- *   along with iTop. If not, see <http: *www.gnu.org/licenses/>
- *
- */
-
-/**
- * Mock class used by @see \Combodo\iTop\Test\UnitTest\Core\HTMLDOMSanitizerTest
- *
- */
-class InlineImage
-{
-	private static $iCallCounter = 0;
-
-	public static function ProcessImageTag(DOMNode $oNode)
-	{
-		self::$iCallCounter++;
-	}
-
-	public static function GetCallCounter()
-	{
-		return self::$iCallCounter;
-	}
-}
\ No newline at end of file