diff --git a/htdocs/categories/class/categorie.class.php b/htdocs/categories/class/categorie.class.php
index 6e1b9083210..08a680c1e1b 100644
--- a/htdocs/categories/class/categorie.class.php
+++ b/htdocs/categories/class/categorie.class.php
@@ -1466,12 +1466,13 @@ class Categorie extends CommonObject
 		// phpcs:enable
 		$ways = array();
 
-		$all_ways = $this->get_all_ways(); // Load array of categories
-		foreach ($all_ways as $way) {
+		$all_ways = $this->get_all_ways(); // Load array of categories to reach this->id
+
+		foreach ($all_ways as $way) {	// It seems we always have 1 entry in this array.
 			$w = array();
 			$i = 0;
 			$forced_color = '';
-			foreach ($way as $cat) {
+			foreach ($way as $cat) {	// Loop on each successive categories to reach the target of current category
 				$i++;
 
 				if (empty($nocolor)) {
@@ -1511,6 +1512,7 @@ class Categorie extends CommonObject
 	// phpcs:disable PEAR.NamingConventions.ValidFunctionName.ScopeNotCamelCaps
 	/**
 	 *	Returns an array containing the list of parent categories
+	 *  Note: A category can only have one parent but this method return an array to work the same way the get_filles is working.
 	 *
 	 *	@return	int|Categorie[] Return integer <0 KO, array OK
 	 */
@@ -1541,7 +1543,7 @@ class Categorie extends CommonObject
 
 	// phpcs:disable PEAR.NamingConventions.ValidFunctionName.ScopeNotCamelCaps
 	/**
-	 * 	Returns in a table all possible paths to get to the category
+	 * 	Returns in a array all possible paths to go to the category
 	 * 	starting with the major categories represented by Tables of categories
 	 *
 	 *	@return	Categorie[][]
@@ -1554,7 +1556,7 @@ class Categorie extends CommonObject
 		$parents = $this->get_meres();
 		if (is_array($parents)) {
 			foreach ($parents as $parent) {
-				$all_ways = $parent->get_all_ways();
+				$all_ways = $parent->get_all_ways();	// recursivity. TODO Add a protection for infinite loop
 				foreach ($all_ways as $way) {
 					$w = $way;
 					$w[] = $this;
@@ -1646,8 +1648,8 @@ class Categorie extends CommonObject
 	}
 
 	/**
-	 * 	Returns categories whose id or name match
-	 * 	add wildcards in the name unless $exact = true
+	 * 	Returns categories whose id or name matches.
+	 * 	It add wildcards in the name unless $exact = true
 	 *
 	 * 	@param		int			$id			Id
 	 * 	@param		string		$nom		Name
diff --git a/htdocs/core/lib/functions.lib.php b/htdocs/core/lib/functions.lib.php
index e436c45cfb5..868815a49b8 100644
--- a/htdocs/core/lib/functions.lib.php
+++ b/htdocs/core/lib/functions.lib.php
@@ -2015,12 +2015,13 @@ function dol_escape_xml($stringtoescape)
  * Return a string label (so on 1 line only and that should not contains any HTML) ready to be output on HTML page.
  * To use text that is not HTML content inside an attribute, you can simply use only dol_escape_htmltag(). In doubt, use dolPrintHTMLForAttribute().
  *
- * @param	string	$s		String to print
- * @return	string			String ready for HTML output
+ * @param	string	$s						String to print
+ * @param	int		$escapeonlyhtmltags		1=Escape only html tags, not the special chars like accents.
+ * @return	string							String ready for HTML output
  */
-function dolPrintLabel($s)
+function dolPrintLabel($s, $escapeonlyhtmltags = 0)
 {
-	return dol_escape_htmltag(dol_string_nohtmltag($s, 1, 'UTF-8', 0, 0), 0, 0, '', 0, 1);
+	return dol_escape_htmltag(dol_string_nohtmltag($s, 1, 'UTF-8', 0, 0), 0, 0, '', $escapeonlyhtmltags, 1);
 }
 
 /**
@@ -2051,18 +2052,23 @@ function dolPrintHTML($s, $allowiframe = 0)
 }
 
 /**
- * Return a string ready to be output on an HTML attribute (alt, title, data-html, ...)
+ * Return a string ready to be output into an HTML attribute (alt, title, data-html, ...)
  * With dolPrintHTMLForAttribute(), the content is HTML encode, even if it is already HTML content.
  *
- * @param	string	$s		String to print
- * @return	string			String ready for HTML output
+ * @param	string	$s						String to print
+ * @param	int		$escapeonlyhtmltags		1=Escape only html tags, not the special chars like accents.
+ * @return	string							String ready for HTML output
  * @see dolPrintHTML(), dolPrintHTMLFortextArea()
  */
-function dolPrintHTMLForAttribute($s)
+function dolPrintHTMLForAttribute($s, $escapeonlyhtmltags = 0)
 {
-	// The dol_htmlentitiesbr will convert simple text into html
-	// The dol_escape_htmltag will escape html chars.
-	return dol_escape_htmltag(dol_string_onlythesehtmltags(dol_htmlentitiesbr($s), 1, 0, 0, 0, array('br', 'b', 'font', 'hr', 'span')), 1, -1, '', 0, 1);
+	// The dol_htmlentitiesbr will convert simple text into html, including switching accent into HTML entities
+	// The dol_escape_htmltag will escape html tags.
+	if ($escapeonlyhtmltags) {
+		return dol_escape_htmltag(dol_string_onlythesehtmltags($s, 1, 0, 0, 0, array('br', 'b', 'font', 'hr', 'span')), 1, -1, '', 1, 1);
+	} else {
+		return dol_escape_htmltag(dol_string_onlythesehtmltags(dol_htmlentitiesbr($s), 1, 0, 0, 0, array('br', 'b', 'font', 'hr', 'span')), 1, -1, '', 0, 1);
+	}
 }
 
 /**
diff --git a/htdocs/core/lib/website.lib.php b/htdocs/core/lib/website.lib.php
index c9cbbb6dafa..697d3f5674d 100644
--- a/htdocs/core/lib/website.lib.php
+++ b/htdocs/core/lib/website.lib.php
@@ -509,14 +509,15 @@ function dolWebsiteSaveContent($content)
 /**
  * Make a redirect to another container.
  *
- * @param 	string	$containerref		Ref of container to redirect to (Example: 'mypage' or 'mypage.php').
- * @param 	string	$containeraliasalt	Ref of alternative aliases to redirect to.
- * @param 	int		$containerid		Id of container.
- * @param	int<0,1>	$permanent			0=Use temporary redirect 302, 1=Use permanent redirect 301
- * @param 	array<string,mixed>	$parameters			Array of parameters to append to the URL.
+ * @param 	string		$containerref			Ref of container to redirect to (Example: 'mypage' or 'mypage.php').
+ * @param 	string		$containeraliasalt		Ref of alternative aliases to redirect to.
+ * @param 	int			$containerid			Id of container.
+ * @param	int<0,1>	$permanent				0=Use temporary redirect 302 (default), 1=Use permanent redirect 301
+ * @param 	array<string,mixed>	$parameters		Array of parameters to append to the URL.
+ * @param	int<0,1>	$parampropagation		0=Do not propagate query parameter in URL when doing the redirect, 1=Keep parameters (default)
  * @return  void
  */
-function redirectToContainer($containerref, $containeraliasalt = '', $containerid = 0, $permanent = 0, $parameters = array())
+function redirectToContainer($containerref, $containeraliasalt = '', $containerid = 0, $permanent = 0, $parameters = array(), $parampropagation = 1)
 {
 	global $db, $website;
 	'@phan-var-force Website $website';
@@ -572,7 +573,9 @@ function redirectToContainer($containerref, $containeraliasalt = '', $containeri
 		}
 	} else { // When page called from virtual host server
 		$newurl = '/'.$containerref.'.php';
-		$newurl .= (empty($_SERVER["QUERY_STRING"]) ? '' : '?'.$_SERVER["QUERY_STRING"]);
+		if ($parampropagation) {
+			$newurl .= (empty($_SERVER["QUERY_STRING"]) ? '' : '?'.$_SERVER["QUERY_STRING"]);
+		}
 	}
 
 	if ($newurl) {
diff --git a/htdocs/core/lib/website2.lib.php b/htdocs/core/lib/website2.lib.php
index fb161162679..5438789e826 100644
--- a/htdocs/core/lib/website2.lib.php
+++ b/htdocs/core/lib/website2.lib.php
@@ -215,17 +215,17 @@ function dolSavePageContent($filetpl, Website $object, WebsitePage $objectpage,
 			$canonicalurladdidlang = '';
 			if ($objectpage->lang) {	// A language is forced on the page, it means we may have other language files with hard links into properties of page
 				$canonicalurl = (($objectpage->id == $object->fk_default_home) ? '/' : (($shortlangcode != substr($object->lang, 0, 2) ? '/'.$shortlangcode : '').'/'.$objectpage->pageurl.'.php'));
-			} else {					// No language forced, it means the canonical is the one with
+			} else {					// No language forced, it means the canonical is the one with params making url unique
 				$canonicalurl = '/'.$objectpage->pageurl.'.php';
 
 				if ($object->lang && $listofaltlang) {
 					$tmpshortlangcode = preg_replace('/[_-].*$/', '', $object->lang); // en_US or en-US -> en
 					// Add parameter ID required to be unique/canonical
-					$canonicalurladdidlang = '<?php echo GETPOSTINT("id") ? "?id=".GETPOSTINT("id")."&" : (GETPOSTINT("cat") ? "?cat=".GETPOSTINT("cat")."&" : "?") ?>';
-					$canonicalurladdidlang .= 'l=<?php echo $weblangs->shortlang ? $weblangs->shortlang : "'.$tmpshortlangcode.'"; ?>';
+					$canonicalurladdidlang = '?__SEO_CANONICAL_URL_PARAMS__';
+					$canonicalurladdidlang .= '&l=<?php echo $weblangs->shortlang ? $weblangs->shortlang : "'.$tmpshortlangcode.'"; ?>';
 				} else {
 					// Add parameter ID required to be unique/canonical
-					$canonicalurladdidlang = '<?php echo GETPOSTINT("id") ? "?id=".GETPOSTINT("id") : (GETPOSTINT("cat") ? "?cat=".GETPOSTINT("cat") : "") ?>';
+					$canonicalurladdidlang = '?__SEO_CANONICAL_URL_PARAMS__';
 				}
 			}
 
@@ -278,20 +278,20 @@ function dolSavePageContent($filetpl, Website $object, WebsitePage $objectpage,
 					$tplcontent .= '<link rel="alternate" hreflang="'.$shortlangcode.'" href="<?php echo $website->virtualhost; ?>'.(($object->fk_default_home == $objectpage->id) ? '/' : (($shortlangcode != substr($object->lang, 0, 2)) ? '/'.$shortlangcode : '').'/'.$objectpage->pageurl.'.php').'" />'."\n";
 
 					$tplcontent .= '<?php } ?>'."\n";
-				} else {
+				} else {					// No language forced, it means the canonical is the one withparams making url unique
 					$canonicalurl = '/'.$objectpage->pageurl.'.php';
 					$arrayofaltlang = explode(',', $listofaltlang);
 
 					foreach ($arrayofaltlang as $altlang) {
 						// Add parameter ID required to be unique/canonical
-						$canonicalurladdidlang = '<?php echo GETPOSTINT("id") ? "?id=".GETPOSTINT("id")."&" : (GETPOSTINT("cat") ? "?cat=".GETPOSTINT("cat")."&" : "?") ?>';
-						$canonicalurladdidlang .= 'l='.$altlang;
+						$canonicalurladdidlang = '?__SEO_CANONICAL_URL_PARAMS__';
+						$canonicalurladdidlang .= '&l='.$altlang;
 						$tplcontent .= '<link rel="alternate" hreflang="'.$altlang.'" href="<?php echo $website->virtualhost; ?>'.$canonicalurl.$canonicalurladdidlang.'" />'."\n";
 					}
 
 					$tmpshortlangcode = preg_replace('/[_-].*$/', '', $object->lang); // en_US or en-US -> en
-					$canonicalurladdidlang = '<?php echo GETPOSTINT("id") ? "?id=".GETPOSTINT("id")."&" : (GETPOSTINT("cat") ? "?cat=".GETPOSTINT("cat")."&" : "?") ?>';
-					$canonicalurladdidlang .= 'l='.$tmpshortlangcode;
+					$canonicalurladdidlang = '?__SEO_CANONICAL_URL_PARAMS__';
+					$canonicalurladdidlang .= '&l='.$tmpshortlangcode;
 					$tplcontent .= '<link rel="alternate" hreflang="'.$tmpshortlangcode.'" href="<?php echo $website->virtualhost; ?>'.$canonicalurl.$canonicalurladdidlang.'" />'."\n";
 				}
 			}
@@ -320,29 +320,34 @@ function dolSavePageContent($filetpl, Website $object, WebsitePage $objectpage,
 		$tplcontent .= '<?php // BEGIN PHP'."\n";
 		$tplcontent .= '$tmp = ob_get_contents(); ob_end_clean();'."\n";	// replace with ob_get_clean ?
 
+		$tplcontent .= "// Now fix the content for SEO or multilanguage\n";
 		// Old method for custom SEO
-		if (strpos($objectpage->content, '$__PAGE__TITLE__') !== false) {
-			$tplcontent .= '$tmp = preg_replace("/<title>.*?<\/title>/s", "<title>" . dol_escape_htmltag($__PAGE__TITLE__) . "</title>", $tmp);'."\n";
-			$tplcontent .= '$tmp = preg_replace("/<meta name=\"title\" content=\".*?\" \/>/s", "<meta name=\"title\" content=\"" . dol_string_nohtmltag($__PAGE__TITLE__) . "\"  />", $tmp);';
-		}
 		if (strpos($objectpage->content, '$__PAGE__KEYWORDS__') !== false) {
-			$tplcontent .= '$tmp = preg_replace("/<meta name=\"keywords\" content=\".*?\" \/>/s", "<meta name=\"keywords\" content=\"" . dol_string_nohtmltag($__PAGE__KEYWORDS__) . "\"  />", $tmp);';
+			$tplcontent .= '$tmp = preg_replace("/^<meta name=\"keywords\" content=\".*?\" \/>/ms", "<meta name=\"keywords\" content=\"" . dolPrintHTMLForAttribute($__PAGE__KEYWORDS__, 1) . "\"  />", $tmp);'."\n";
+		}
+		if (strpos($objectpage->content, '$__PAGE__TITLE__') !== false) {
+			$tplcontent .= '$tmp = preg_replace("/^<title>.*?<\/title>/ms", "<title>" . dolPrintHTMLForAttribute($__PAGE__TITLE__, 1) . "</title>", $tmp);'."\n";
+			$tplcontent .= '$tmp = preg_replace("/^<meta name=\"title\" content=\".*?\" \/>/ms", "<meta name=\"title\" content=\"" . dolPrintHTMLForAttribute($__PAGE__TITLE__, 1) . "\"  />", $tmp);'."\n";
 		}
 		if (strpos($objectpage->content, '$__PAGE__DESC__') !== false) {
-			$tplcontent .= '$tmp = preg_replace("/<meta name=\"description\" content=\".*?\" \/>/s", "<meta name=\"description\" content=\"" . dol_string_nohtmltag($__PAGE__DESC__) . "\"  />", $tmp);';
+			$tplcontent .= '$tmp = preg_replace("/^<meta name=\"description\" content=\".*?\" \/>/ms", "<meta name=\"description\" content=\"" . dolPrintHTMLForAttribute($__PAGE__DESC__, 1) . "\"  />", $tmp);'."\n";
 		}
 		// New method for custom SEO
-		if (strpos($objectpage->content, 'define("__SEO_PAGE_TITLE__"') !== false) {
-			$tplcontent .= '$tmp = preg_replace("/<title>.*?<\/title>/s", "<title>" . dol_escape_htmltag(constant("__SEO_PAGE_TITLE__")) . "</title>", $tmp);'."\n";
-			$tplcontent .= '$tmp = preg_replace("/<meta name=\"title\" content=\".*?\" \/>/s", "<meta name=\"title\" content=\"" . dol_string_nohtmltag(constant("__SEO_PAGE_TITLE__")) . "\"  />", $tmp);';
-		}
 		if (strpos($objectpage->content, 'define("__SEO_PAGE_KEYWORDS__"') !== false) {
-			$tplcontent .= '$tmp = preg_replace("/<meta name=\"keywords\" content=\".*?\" \/>/s", "<meta name=\"keywords\" content=\"" . dol_string_nohtmltag(constant("__SEO_PAGE_KEYWORDS__")) . "\"  />", $tmp);';
+			$tplcontent .= '$tmp = preg_replace("/^<meta name=\"keywords\" content=\".*?\" \/>/ms", "<meta name=\"keywords\" content=\"" . dolPrintHTMLForAttribute(constant("__SEO_PAGE_KEYWORDS__"), 1) . "\"  />", $tmp);'."\n";
+		}
+		if (strpos($objectpage->content, 'define("__SEO_PAGE_TITLE__"') !== false) {
+			$tplcontent .= '$tmp = preg_replace("/^<title>.*?<\/title>/ms", "<title>" . dolPrintHTMLForAttribute(constant("__SEO_PAGE_TITLE__"), 1) . "</title>", $tmp);'."\n";
+			$tplcontent .= '$tmp = preg_replace("/^<meta name=\"title\" content=\".*?\" \/>/ms", "<meta name=\"title\" content=\"" . dolPrintHTMLForAttribute(constant("__SEO_PAGE_TITLE__"), 1) . "\"  />", $tmp);'."\n";
 		}
 		if (strpos($objectpage->content, 'define("__SEO_PAGE_DESC__"') !== false) {
-			$tplcontent .= '$tmp = preg_replace("/<meta name=\"description\" content=\".*?\" \/>/s", "<meta name=\"description\" content=\"" . dol_string_nohtmltag(constant("__SEO_PAGE_DESC__")) . "\"  />", $tmp);';
+			$tplcontent .= '$tmp = preg_replace("/^<meta name=\"description\" content=\".*?\" \/>/ms", "<meta name=\"description\" content=\"" . dolPrintHTMLForAttribute(constant("__SEO_PAGE_DESC__"), 1) . "\"  />", $tmp);'."\n";
+		}
+		if (empty($objectpage->lang)) {		// We may need to use param into the canonical url
+			$tplcontent .= 'defined("__SEO_CANONICAL_URL_PARAMS__") ? ($tmp = preg_replace("/__SEO_CANONICAL_URL_PARAMS__/", dolPrintHTMLForAttributeUrl(constant("__SEO_CANONICAL_URL_PARAMS__")), $tmp)) : ($tmp = preg_replace("/\?__SEO_CANONICAL_URL_PARAMS__\"/", "", preg_replace("/\?__SEO_CANONICAL_URL_PARAMS__&/", "?", $tmp)));'."\n";
 		}
 
+		$tplcontent .= "// Now output the generated page content\n";
 		$tplcontent .= 'dolWebsiteOutput($tmp, "html", '.((int) $objectpage->id).'); dolWebsiteIncrementCounter('.((int) $object->id).', "'.$objectpage->type_container.'", '.((int) $objectpage->id).');'."\n";
 		$tplcontent .= "// END PHP ?>\n";
 	} else {