diff --git a/i18n/i18nTextCollector.php b/i18n/i18nTextCollector.php
index da112c709..4129ba5c1 100644
--- a/i18n/i18nTextCollector.php
+++ b/i18n/i18nTextCollector.php
@@ -71,10 +71,21 @@ class i18nTextCollector extends Object {
 	 * @uses DataObject->collectI18nStatics()
 	 * 
 	 * @param array $restrictToModules
+	 * @param array $mergeWithExisting Merge new master strings with existing ones
+	 * already defined in language files, rather than replacing them. This can be useful
+	 * for long-term maintenance of translations across releases, because it allows
+	 * "translation backports" to older releases without removing strings these older releases
+	 * still rely on.
 	 */	
-	public function run($restrictToModules = null) {
-		//Debug::message("Collecting text...", false);
-		
+	public function run($restrictToModules = null, $mergeWithExisting = false) {
+		$entitiesByModule = $this->collect($restrictToModules, $mergeWithExisting);
+		// Write each module language file
+		if($entitiesByModule) foreach($entitiesByModule as $module => $entities) {
+			$this->getWriter()->write($entities, $this->defaultLocale, $this->baseSavePath . '/' . $module);
+		}
+	}
+
+	public function collect($restrictToModules = null, $mergeWithExisting = false) {
 		$modules = scandir($this->basePath);
 		$themeFolders = array();
 		
@@ -137,7 +148,31 @@ class i18nTextCollector extends Object {
 					$entitiesByModule[$othermodule][$fullName] = $spec;
 					unset($entitiesByModule[$module][$fullName]);
 				}
-			}			
+			}		
+
+			// Optionally merge with existing master strings
+			// TODO Support all defined source formats through i18n::get_translators().
+			//      Currently not possible because adapter instances can't be fully reset through the Zend API,
+			//      meaning master strings accumulate across modules
+			if($mergeWithExisting) {
+				$adapter = Injector::inst()->get('i18nRailsYamlAdapter');
+				$masterFile = "{$this->basePath}/{$module}/lang/" 
+					. $adapter->getFilenameForLocale($this->defaultLocale);
+				if(!file_exists($masterFile)) continue;
+
+				$adapter->addTranslation(array(
+					'content' => $masterFile,
+					'locale' => $this->defaultLocale
+				));
+				$entitiesByModule[$module] = array_merge(
+					array_map(
+						// Transform each master string from scalar value to array of strings
+						function($v) {return array($v);},
+						$adapter->getMessages($this->defaultLocale)
+					),
+					$entitiesByModule[$module]
+				);	
+			}
 		}
 
 		// Restrict modules we update to just the specified ones (if any passed)
@@ -147,10 +182,11 @@ class i18nTextCollector extends Object {
 			}
 		}
 
-		// Write each module language file
-		if($entitiesByModule) foreach($entitiesByModule as $module => $entities) {
-			$this->getWriter()->write($entities, $this->defaultLocale, $this->baseSavePath . '/' . $module);
-		}
+		return $entitiesByModule;
+	}
+
+	public function write($module, $entities) {
+		$this->getWriter()->write($entities, $this->defaultLocale, $this->baseSavePath . '/' . $module);
 	}
 	
 	/**
diff --git a/tasks/i18nTextCollectorTask.php b/tasks/i18nTextCollectorTask.php
index 1f39f3d5a..4e36e9038 100644
--- a/tasks/i18nTextCollectorTask.php
+++ b/tasks/i18nTextCollectorTask.php
@@ -10,6 +10,12 @@ class i18nTextCollectorTask extends BuildTask {
 	protected $description = "
 		Traverses through files in order to collect the 'entity master tables'
 		stored in each module.
+
+		Parameters:
+		- locale: Sets default locale
+		- writer: Custom writer class (defaults to i18nTextCollector_Writer_RailsYaml)
+		- module: One or more modules to limit collection (comma-separated)
+		- merge: Merge new strings with existing ones already defined in language files (default: FALSE)
 	";
 	
 	public function init() {
@@ -32,6 +38,6 @@ class i18nTextCollectorTask extends BuildTask {
 		$writer = $request->getVar('writer');
 		if($writer) $c->setWriter(new $writer());
 		$restrictModules = ($request->getVar('module')) ? explode(',', $request->getVar('module')) : null;
-		return $c->run($restrictModules);
+		return $c->run($restrictModules, (bool)$request->getVar('merge'));
 	}
 }
diff --git a/tests/filesystem/FileTest.php b/tests/filesystem/FileTest.php
index db2d8c8b1..ed716eedc 100644
--- a/tests/filesystem/FileTest.php
+++ b/tests/filesystem/FileTest.php
@@ -15,8 +15,8 @@ class FileTest extends SapphireTest {
 		$parser = new ShortcodeParser();
 		$parser->register('file_link', array('File', 'link_shortcode_handler'));
 
-		$fileShortcode = sprintf('[file_link id=%d]', $testFile->ID);
-		$fileEnclosed  = sprintf('[file_link id=%d]Example Content[/file_link]', $testFile->ID);
+		$fileShortcode = sprintf('[file_link,id=%d]', $testFile->ID);
+		$fileEnclosed  = sprintf('[file_link,id=%d]Example Content[/file_link]', $testFile->ID);
 
 		$fileShortcodeExpected = $testFile->Link();
 		$fileEnclosedExpected  = sprintf(
@@ -27,11 +27,11 @@ class FileTest extends SapphireTest {
 
 		$testFile->delete();
 
-		$fileShortcode = '[file_link id="-1"]';
-		$fileEnclosed  = '[file_link id="-1"]Example Content[/file_link]';
+		$fileShortcode = '[file_link,id="-1"]';
+		$fileEnclosed  = '[file_link,id="-1"]Example Content[/file_link]';
 
 		$this->assertEquals('', $parser->parse('[file_link]'), 'Test that invalid ID attributes are not parsed.');
-		$this->assertEquals('', $parser->parse('[file_link id="text"]'));
+		$this->assertEquals('', $parser->parse('[file_link,id="text"]'));
 		$this->assertEquals('', $parser->parse('[file_link]Example Content[/file_link]'));
 
 		if(class_exists('ErrorPage')) {
diff --git a/tests/i18n/_fakewebroot/i18ntestmodule/templates/i18nTestModule.ss b/tests/i18n/_fakewebroot/i18ntestmodule/templates/i18nTestModule.ss
index 5cc818354..1c245b670 100644
--- a/tests/i18n/_fakewebroot/i18ntestmodule/templates/i18nTestModule.ss
+++ b/tests/i18n/_fakewebroot/i18ntestmodule/templates/i18nTestModule.ss
@@ -1,3 +1,4 @@
 <% _t('i18nTestModule.MAINTEMPLATE',"Main Template") %>
 $Layout
-lonely _t() call that should be ignored
\ No newline at end of file
+lonely _t() call that should be ignored
+<% _t('i18nTestModule.NEWENTITY',"Not stored in master file yet") %>
\ No newline at end of file
diff --git a/tests/i18n/i18nTextCollectorTest.php b/tests/i18n/i18nTextCollectorTest.php
index 888f9998b..04fcbcb35 100644
--- a/tests/i18n/i18nTextCollectorTest.php
+++ b/tests/i18n/i18nTextCollectorTest.php
@@ -538,6 +538,30 @@ YAML;
 		
 		Config::inst()->update('SSViewer', 'theme', $theme);
 	}
+
+	public function testCollectMergesWithExisting() {
+		$defaultlocal = i18n::default_locale();
+		$local = i18n::get_locale();
+		i18n::set_locale('en_US'); 
+		i18n::set_default_locale('en_US');
+
+		$c = new i18nTextCollector();
+		$c->setWriter(new i18nTextCollector_Writer_Php());
+		$c->basePath = $this->alternateBasePath;
+		$c->baseSavePath = $this->alternateBaseSavePath;
+		
+		$entitiesByModule = $c->collect(null, true /* merge */);
+		$this->assertArrayHasKey(
+			'i18nTestModule.ENTITY',
+			$entitiesByModule['i18ntestmodule'],
+			'Retains existing entities'
+		);
+		$this->assertArrayHasKey(
+			'i18nTestModule.NEWENTITY',
+			$entitiesByModule['i18ntestmodule'],
+			'Adds new entities'
+		);
+	}
 	
 	public function testCollectFromFilesystemAndWriteMasterTables() {
 		$defaultlocal = i18n::default_locale();