Index: branches/RC/core/install/install_schema.sql
===================================================================
diff -u -N -r10887 -r10906
--- branches/RC/core/install/install_schema.sql	(.../install_schema.sql)	(revision 10887)
+++ branches/RC/core/install/install_schema.sql	(.../install_schema.sql)	(revision 10906)
@@ -134,6 +134,7 @@
   ThousandSep VARCHAR(10) NOT NULL DEFAULT '',
   `Charset` varchar(20) NOT NULL default '',
   UnitSystem tinyint(4) NOT NULL default '1',
+  FilenameReplacements TEXT NULL,
   PRIMARY KEY  (LanguageId),
   KEY Enabled (Enabled),
   KEY PrimaryLang (PrimaryLang),
Index: branches/RC/core/install/upgrades.sql
===================================================================
diff -u -N -r10887 -r10906
--- branches/RC/core/install/upgrades.sql	(.../upgrades.sql)	(revision 10887)
+++ branches/RC/core/install/upgrades.sql	(.../upgrades.sql)	(revision 10906)
@@ -343,3 +343,9 @@
 INSERT INTO Permissions VALUES(DEFAULT, 'in-portal:agents.edit', 11, 1, 1, 0);
 INSERT INTO Permissions VALUES(DEFAULT, 'in-portal:agents.add', 11, 1, 1, 0);
 INSERT INTO Permissions VALUES(DEFAULT, 'in-portal:agents.view', 11, 1, 1, 0);
+
+INSERT INTO ConfigurationAdmin VALUES ('FilenameSpecialCharReplacement', 'la_Text_General', 'la_config_FilenameSpecialCharReplacement', 'select', NULL, '_=+_,-=+-', 10.16, 0, 0);
+INSERT INTO ConfigurationValues VALUES (DEFAULT, 'FilenameSpecialCharReplacement', '_', 'In-Portal', 'in-portal:configure_categories');
+
+ALTER TABLE `Language` ADD `FilenameReplacements` TEXT NULL ;
+
Index: branches/RC/core/admin_templates/regional/languages_edit.tpl
===================================================================
diff -u -N -r9854 -r10906
--- branches/RC/core/admin_templates/regional/languages_edit.tpl	(.../languages_edit.tpl)	(revision 9854)
+++ branches/RC/core/admin_templates/regional/languages_edit.tpl	(.../languages_edit.tpl)	(revision 10906)
@@ -78,6 +78,7 @@
 		<inp2:m_RenderElement name="inp_edit_box" prefix="lang" field="Priority" title="la_fld_Priority"/>
 		<inp2:m_RenderElement name="inp_edit_checkbox" prefix="lang" field="Enabled" title="!la_fld_Enabled!"/>
 		<inp2:m_RenderElement name="inp_edit_options" prefix="lang" field="UnitSystem" title="!la_fld_UnitSystem!"/>
+		<inp2:m_RenderElement name="inp_edit_textarea" prefix="lang" field="FilenameReplacements" title="la_fld_FilenameReplacements" cols="50" rows="10"/>
 	<inp2:m_if check="lang_IsNewMode">
 	<tr class="<inp2:m_odd_even odd="table-color1" even="table-color2"/>">
 		<inp2:m_inc param="tab_index" by="1"/>
Index: branches/RC/core/units/general/helpers/filenames_helper.php
===================================================================
diff -u -N -r10098 -r10906
--- branches/RC/core/units/general/helpers/filenames_helper.php	(.../filenames_helper.php)	(revision 10098)
+++ branches/RC/core/units/general/helpers/filenames_helper.php	(.../filenames_helper.php)	(revision 10906)
@@ -1,23 +1,78 @@
 <?php
 
 class kFilenamesHelper extends kHelper {
+	
 	/**
+	 * Character, that should replace disallowed symbols in filename
+	 *
+	 * @var string
+	 */
+	var $_escapeChar = '_';
+
+	/**
+	 * Sequences, that should be replaced with mathing sequences from _filenameReplaceTo property
+	 *
+	 * @var Array
+	 */
+	var $_filenameReplaceFrom = Array ();
+
+	/**
+	 * Sequences, that will replace matching sequences from _filenameReplaceFrom property
+	 *
+	 * @var Array
+	 */
+	var $_filenameReplaceTo = Array ();
+	
+	
+	function kFilenamesHelper()
+	{
+		parent::kHelper();
+
+		$this->_escapeChar = $this->Application->ConfigValue('FilenameSpecialCharReplacement');
+
+		$language =& $this->Application->recallObject('lang.current');
+		/* @var $language kDBItem */
+
+		$replacements = $language->GetDBField('FilenameReplacements');
+		if ($replacements) {
+			$replacements = explode("\r\n", $replacements);
+			foreach ($replacements as $replacement) {
+				list ($replace_from, $replace_to) = explode('=', $replacement);
+				$this->_filenameReplaceFrom[] = trim($replace_from);
+				$this->_filenameReplaceTo[] = trim($replace_to);
+			}
+		}
+	}
+
+	function replaceSequences($filename)
+	{
+		$not_allowed = Array (
+			' ', '\\', '/', ':', '*', '?', '"', '<', '>', '|', '`',
+			'~', '!', '@', '#', '$', '%', '^', '&', '(', ')', '~',
+			'+', '=', '-', '{', '}', ']', '[', "'", ';', '.', ',', "\r", "\n"
+		);
+
+		if ($this->_filenameReplaceFrom) {
+			// replace predefined sequences
+			$filename = str_replace($this->_filenameReplaceFrom, $this->_filenameReplaceTo, $filename);
+		}
+
+		$filename = str_replace($not_allowed, $this->_escapeChar, $filename);
+		$filename = preg_replace('/(' . $this->_escapeChar . '+)/', $this->_escapeChar, $filename);
+		return trim($filename, $this->_escapeChar); // remove trailing escape chars
+	}
+
+	/**
 	 * replace not allowed symbols with "_" chars + remove duplicate "_" chars in result
 	 *
 	 * @param string $string
 	 * @return string
 	 */
 	function stripDisallowed($table, $id_field, $item_id, $filename)
 	{
-		$not_allowed = Array(	' ', '\\', '/', ':', '*', '?', '"', '<', '>', '|', '`',
-		'~', '!', '@', '#', '$', '%', '^', '&', '(', ')', '~',
-		'+', '=', '-', '{', '}', ']', '[', "'", ';', '.', ',', "\r", "\n");
+		$filename = $this->replaceSequences($filename);
 
-		$filename = str_replace($not_allowed, '_', $filename);
-		$filename = preg_replace('/(_+)/', '_', $filename);
-		$filename = $this->checkAutoFilename($table, $id_field, $item_id, $filename);
-
-		return $filename;
+		return $this->checkAutoFilename($table, $id_field, $item_id, $filename);
 	}
 
 	function checkAutoFilename($table, $id_field, $item_id, $filename)
Index: branches/RC/core/units/categories/categories_item.php
===================================================================
diff -u -N -r10780 -r10906
--- branches/RC/core/units/categories/categories_item.php	(.../categories_item.php)	(revision 10780)
+++ branches/RC/core/units/categories/categories_item.php	(.../categories_item.php)	(revision 10906)
@@ -53,7 +53,8 @@
 
 			return $parent_path.$this->GetID().'|';
 		}
-
+		
+		
 		/**
 		 * replace not allowed symbols with "_" chars + remove duplicate "_" chars in result
 		 *
@@ -62,16 +63,14 @@
 		 */
 		function stripDisallowed($string)
 		{
-			$not_allowed = Array(	' ', '\\', '/', ':', '*', '?', '"', '<', '>', '|', '`',
-			'~', '!', '@', '#', '$', '%', '^', '&', '(', ')', '~',
-			'+', '=', '-', '{', '}', ']', '[', "'", ';', '.', ',');
+			$filenames_helper =& $this->Application->recallObject('FilenamesHelper');
+			/* @var $filenames_helper EFilenameHelper */
 
-			$string = str_replace($not_allowed, '_', $string);
-			$string = preg_replace('/(_+)/', '_', $string);
-			$string = $this->checkAutoFilename($string);
+			$string = $filenames_helper->replaceSequences($string);
 
-			return $string;
+			return $this->checkAutoFilename($string);
 		}
+		
 
 		function checkFilename()
 		{
@@ -87,6 +86,8 @@
 		{
 			if(!$filename) return $filename;
 
+			$escape_char = $this->Application->ConfigValue('FilenameSpecialCharReplacement');
+			
 			$item_id = !$this->GetID() ? 0 : $this->GetID();
 			$check_in_parent_cat_only = $item_id ? ' AND ParentId = '.$this->GetDBField("ParentId") : '';
 
@@ -105,11 +106,11 @@
 			$duplicates_found = (count($found_item_ids) > 1) || ($found_item_ids && $found_item_ids[0] != $item_id);
 			if ($duplicates_found || $has_page) // other category has same filename as ours OR we have filename, that ends with _number
 			{
-				$append = $duplicates_found ? '_a' : '';
+				$append = $duplicates_found ? $escape_char . 'a' : '';
 				if($has_page)
 				{
 					$filename = $rets[1].'_'.$rets[2];
-					$append = $rets[3] ? $rets[3] : '_a';
+					$append = $rets[3] ? $rets[3] : $escape_char . 'a';
 				}
 
 				// check live & temp table
Index: branches/RC/core/install/english.lang
===================================================================
diff -u -N -r10898 -r10906
--- branches/RC/core/install/english.lang	(.../english.lang)	(revision 10898)
+++ branches/RC/core/install/english.lang	(.../english.lang)	(revision 10906)
@@ -6,7 +6,9 @@
 			<PHRASE Label="la_col_NextRunOn" Module="Core" Type="1">TmV4dCBSdW4gT24=</PHRASE>
 			<PHRASE Label="la_col_RunInterval" Module="Core" Type="1">UnVuIEludGVydmFs</PHRASE>
 			<PHRASE Label="la_col_RunMode" Module="Core" Type="1">UnVuIE1vZGU=</PHRASE>
+			<PHRASE Label="la_config_FilenameSpecialCharReplacement" Module="Core" Type="1">RmlsZW5hbWUgU3BlY2lhbCBDaGFyIFJlcGxhY2VtZW50</PHRASE>
 			<PHRASE Label="la_fld_Event" Module="Core" Type="1">RXZlbnQ=</PHRASE>
+			<PHRASE Label="la_fld_FilenameReplacements" Module="Core" Type="1">RmlsZW5hbWUgUmVwbGFjZW1lbnRz</PHRASE>
 			<PHRASE Label="la_fld_LastRunOn" Module="Core" Type="1">TGFzdCBSdW4gT24=</PHRASE>
 			<PHRASE Label="la_fld_LastRunStatus" Module="Core" Type="1">TGFzdCBSdW4gU3RhdHVz</PHRASE>
 			<PHRASE Label="la_fld_NextRunOn" Module="Core" Type="1">TmV4dCBSdW4gT24=</PHRASE>
Index: branches/RC/core/install/install_data.sql
===================================================================
diff -u -N -r10887 -r10906
--- branches/RC/core/install/install_data.sql	(.../install_data.sql)	(revision 10887)
+++ branches/RC/core/install/install_data.sql	(.../install_data.sql)	(revision 10906)
@@ -62,6 +62,7 @@
 INSERT INTO ConfigurationAdmin VALUES ('UseJSRedirect', 'la_Text_Website', 'la_config_use_js_redirect', 'checkbox', '', '', 10.14, 0, 0);
 INSERT INTO ConfigurationAdmin VALUES ('MaxImportCategoryLevels', 'la_Text_General', 'la_prompt_max_import_category_levels', 'text', '', '', 10.08, 0, 1);
 INSERT INTO ConfigurationAdmin VALUES ('UseCronForRegularEvent', 'la_Text_Website', 'la_UseCronForRegularEvent', 'checkbox', NULL, NULL, 10.15, 0, 0);
+INSERT INTO ConfigurationAdmin VALUES ('FilenameSpecialCharReplacement', 'la_Text_General', 'la_config_FilenameSpecialCharReplacement', 'select', NULL, '_=+_,-=+-', 10.16, 0, 0);
 INSERT INTO ConfigurationAdmin VALUES ('NoPermissionTemplate', 'la_Text_Website', 'la_config_nopermission_template', 'text', '', '', 10.17, 0, 0);
 INSERT INTO ConfigurationAdmin VALUES ('UseOutputCompression', 'la_Text_Website', 'la_config_UseOutputCompression', 'checkbox', '', '', 10.18, 0, 1);
 INSERT INTO ConfigurationAdmin VALUES ('OutputCompressionLevel', 'la_Text_Website', 'la_config_OutputCompressionLevel', 'text', '', '', 10.19, 0, 1);
@@ -220,6 +221,7 @@
 INSERT INTO ConfigurationValues VALUES (DEFAULT, 'UseJSRedirect', '0', 'In-Portal', 'in-portal:configure_general');
 INSERT INTO ConfigurationValues VALUES (DEFAULT, 'MaxImportCategoryLevels', '10', 'In-Portal', 'in-portal:configure_categories');
 INSERT INTO ConfigurationValues VALUES (DEFAULT, 'UseCronForRegularEvent', '0', 'In-Portal', 'in-portal:configure_general');
+INSERT INTO ConfigurationValues VALUES (DEFAULT, 'FilenameSpecialCharReplacement', '_', 'In-Portal', 'in-portal:configure_categories');
 INSERT INTO ConfigurationValues VALUES (DEFAULT, 'NoPermissionTemplate', 'no_permission', 'In-Portal', 'in-portal:configure_general');
 INSERT INTO ConfigurationValues VALUES (DEFAULT, 'UseOutputCompression', '0', 'In-Portal', 'in-portal:configure_general');
 INSERT INTO ConfigurationValues VALUES (DEFAULT, 'OutputCompressionLevel', '7', 'In-Portal', 'in-portal:configure_general');
Index: branches/RC/core/units/languages/languages_config.php
===================================================================
diff -u -N -r9936 -r10906
--- branches/RC/core/units/languages/languages_config.php	(.../languages_config.php)	(revision 9936)
+++ branches/RC/core/units/languages/languages_config.php	(.../languages_config.php)	(revision 10906)
@@ -159,6 +159,7 @@
 										'ThousandSep' => Array('type' => 'string','not_null' => 1, 'default' => ''),
 										'Charset' => Array('type' => 'string','not_null' => '1','default' => '','required'=>1),
 										'UnitSystem' => Array('type' => 'int','not_null' => 1, 'default' => 1, 'formatter' => 'kOptionsFormatter','options' => Array(1 => 'la_Metric', 2 => 'la_US_UK'),'use_phrases' => 1),
+										'FilenameReplacements' => Array('type' => 'string'),
 								),
 
 					'VirtualFields'	=> 	Array(