Funktionierende realURL Konfiguration für drei Sprachen mit den Extensions "YAG" und "news". Basis: http://docs.typo3.org/typo3cms/extensions/news/latest/Main/Administration/Realurl/Index.html (advanced Example)

realurl_conf.php

<?php
$TYPO3_CONF_VARS['FE']['addRootLineFields'].= ',tx_realurl_pathsegment';
$TYPO3_CONF_VARS['EXTCONF']['realurl'] = array(
	'encodeSpURL_postProc' => array(
		'yag' => 'EXT:yag/Classes/Hooks/RealUrlHook.php:user_Tx_Yag_Hooks_RealUrl->encodeSpURL_postProc',
	),
	'decodeSpURL_preProc' => array(
		'yag' => 'EXT:yag/Classes/Hooks/RealUrlHook.php:user_Tx_Yag_Hooks_RealUrl->decodeSpURL_preProc',
	),
	'_DEFAULT' => array(
    'pagePath' => array(
          'type' => 'user',
          'userFunc' => 'EXT:realurl/class.tx_realurl_advanced.php:&tx_realurl_advanced->main',
          'spaceCharacter' => '-',
          'languageGetVar' => 'L',
          'expireDays' => '3',
          'rootpage_id' => 1,
          # If set, page shortcuts are not resolved to their destination page.
          #'dontResolveShortcuts' => '1',
    ),
    'init' => array(
        'enableCHashCache' => TRUE,
        'enableCHashCache' => 1,
        'respectSimulateStaticURLs' => 0,
        'enableUrlDecodeCache' => 1,
        'enableUrlEncodeCache' => 1,
				'appendMissingSlash' => 'ifNotFile',
        # Default (blank value) is a 404 page not found from TYPO3s frontend API.
        # "ignore": A silent accept of the remaining parts.
        # "redirect_goodUpperDir": Will compose a URL from the parts successfully mapped and redirect to that.
        'postVarSet_failureMode' => '',
    ),
    'preVars' => array(
        array (
						'GETvar' => 'no_cache',
						'valueMap' => array (
								'nc' => '1',
						),
						'noMatch' => 'bypass'
				),
        array(
            'GETvar' => 'L',
            'valueMap' => array(
									'de' => '0',
									'en' => '1',
									'nl' => '2',
            ),
            'noMatch' => 'bypass',
        ),
    ),
		'fileName' => array (
//
// if you don't want .html-URLs set the following to "false" (e.g. 'defaultToHTMLsuffixOnPrev' => false,)
// then you get http://www.yourdomain.com/imprint/ instead of http://www.yourdomain.com/imprint.html
//
				'defaultToHTMLsuffixOnPrev' => true,
				'index' => array (
						'sitemap.xml' => array (
								'keyValues' => array (
										'type' => '776',
								),
						),
						'rss-newsfeed.xml' => array (
								'keyValues' => array (
										'type' => '9818',
								),
						),
						'rss-newsfeed.html' => array (
								'keyValues' => array (
										'type' => '9818',
								),
						),
				),
		),
    'fixedPostVars' => array(
        'newsDetailConfiguration' => array(
            array(
                'GETvar' => 'tx_news_pi1[news]',
                'lookUpTable' => array(
                    'table' => 'tx_news_domain_model_news',
                    'id_field' => 'uid',
                    'alias_field' => 'title',
                    'addWhereClause' => ' AND NOT deleted',
                    'useUniqueCache' => 1,
                    'useUniqueCache_conf' => array(
                        'strtolower' => 1,
                        'spaceCharacter' => '-'
                    ),
                    'languageGetVar' => 'L',
                    'languageExceptionUids' => '',
                    'languageField' => 'sys_language_uid',
                    'transOrigPointerField' => 'l10n_parent',
                    'autoUpdate' => 1,
                    'expireDays' => 180,
                ),
            ),
        ),
        'newsCategoryConfiguration' => array(
            array(
                'GETvar' => 'tx_news_pi1[overwriteDemand][categories]',
                'lookUpTable' => array(
                    'table' => 'tx_news_domain_model_category',
                    'id_field' => 'uid',
                    'alias_field' => 'title',
                    'addWhereClause' => ' AND NOT deleted',
                    'useUniqueCache' => 1,
                    'useUniqueCache_conf' => array(
                        'strtolower' => 1,
                        'spaceCharacter' => '-'
                    ),
                ),
            ),
        ),
        'newsTagConfiguration' => array(
            array(
                'GETvar' => 'tx_news_pi1[overwriteDemand][tags]',
                'lookUpTable' => array(
                    'table' => 'tx_news_domain_model_tag',
                    'id_field' => 'uid',
                    'alias_field' => 'title',
                    'addWhereClause' => ' AND NOT deleted',
                    'useUniqueCache' => 1,
                    'useUniqueCache_conf' => array(
                        'strtolower' => 1,
                        'spaceCharacter' => '-'
                    ),
                ),
            ),
        ),
				# Set page IDs
        '81' => 'newsDetailConfiguration', // Angebote und Aktionen
        '148' => 'newsDetailConfiguration', // News und Toernberichte
        #'71' => 'newsTagConfiguration',
        #'72' => 'newsCategoryConfiguration',
    ),
    'postVarSets' => array(
        '_DEFAULT' => array(
            'controller' => array(
                array(
                    'GETvar' => 'tx_news_pi1[action]',
                    'noMatch' => 'bypass',
                ),
                array(
                    'GETvar' => 'tx_news_pi1[controller]',
                    'noMatch' => 'bypass',
                ),
            ),
            'dateFilter' => array(
                array(
                    'GETvar' => 'tx_news_pi1[overwriteDemand][year]',
                ),
                array(
                    'GETvar' => 'tx_news_pi1[overwriteDemand][month]',
                ),
            ),
        ),
    ),
	)
);
# Kontrollstruktur für mehrsprachigen 404- Fehlerseiten 
# 0- Deutsch
# 1 - Englisch
# 2 - Niederländisch
if (preg_match('/\/de\//', $_SERVER['REQUEST_URI']) || $_GET['L'] == 0) {
  $TYPO3_CONF_VARS['FE']['pageNotFound_handling'] = '/de/404.html';
} else if (preg_match('/\/en\//', $_SERVER['REQUEST_URI']) || $_GET['L'] == 1) {
  $TYPO3_CONF_VARS['FE']['pageNotFound_handling'] = '/en/404.html';
} else if (preg_match('/\/nl\//', $_SERVER['REQUEST_URI']) || $_GET['L'] == 2) {
  $TYPO3_CONF_VARS['FE']['pageNotFound_handling'] = '/nl/404.html';
} else  {
  $TYPO3_CONF_VARS['FE']['pageNotFound_handling'] = '/en/404.html';
}
?>