diff --git a/boot/boot.js b/boot/boot.js
index 7d0bfa7e2..10ef2a4da 100644
--- a/boot/boot.js
+++ b/boot/boot.js
@@ -1502,7 +1502,7 @@ $tw.boot.startup = function(options) {
 	// Add file extension information
 	$tw.utils.registerFileType("text/vnd.tiddlywiki","utf8",".tid");
 	$tw.utils.registerFileType("application/x-tiddler","utf8",".tid");
-	$tw.utils.registerFileType("application/x-tiddlers","utf8",".tids");
+	$tw.utils.registerFileType("application/x-tiddlers","utf8",".multids");
 	$tw.utils.registerFileType("application/x-tiddler-html-div","utf8",".tiddler");
 	$tw.utils.registerFileType("text/vnd.tiddlywiki2-recipe","utf8",".recipe");
 	$tw.utils.registerFileType("text/plain","utf8",".txt");
diff --git a/core/language/en-GB/ControlPanel.tids b/core/language/en-GB/ControlPanel.multids
similarity index 100%
rename from core/language/en-GB/ControlPanel.tids
rename to core/language/en-GB/ControlPanel.multids
diff --git a/core/language/en-GB/Docs/ModuleTypes.tids b/core/language/en-GB/Docs/ModuleTypes.multids
similarity index 100%
rename from core/language/en-GB/Docs/ModuleTypes.tids
rename to core/language/en-GB/Docs/ModuleTypes.multids
diff --git a/core/language/en-GB/EditTemplate.tids b/core/language/en-GB/EditTemplate.multids
similarity index 100%
rename from core/language/en-GB/EditTemplate.tids
rename to core/language/en-GB/EditTemplate.multids
diff --git a/core/language/en-GB/Docs/Fields.tids b/core/language/en-GB/Fields.multids
similarity index 100%
rename from core/language/en-GB/Docs/Fields.tids
rename to core/language/en-GB/Fields.multids
diff --git a/core/language/en-GB/Notifications.tids b/core/language/en-GB/Notifications.multids
similarity index 100%
rename from core/language/en-GB/Notifications.tids
rename to core/language/en-GB/Notifications.multids
diff --git a/core/language/en-GB/Search.tids b/core/language/en-GB/Search.multids
similarity index 100%
rename from core/language/en-GB/Search.tids
rename to core/language/en-GB/Search.multids
diff --git a/core/language/en-GB/SideBar.tids b/core/language/en-GB/SideBar.multids
similarity index 100%
rename from core/language/en-GB/SideBar.tids
rename to core/language/en-GB/SideBar.multids
diff --git a/core/language/en-GB/TiddlerInfo.tids b/core/language/en-GB/TiddlerInfo.multids
similarity index 100%
rename from core/language/en-GB/TiddlerInfo.tids
rename to core/language/en-GB/TiddlerInfo.multids
diff --git a/editions/tw5.com/tiddlers/howtos/How to create a translation for TiddlyWiki.tid b/editions/tw5.com/tiddlers/howtos/How to create a translation for TiddlyWiki.tid
index 8f1f1b692..ffe6fc6b7 100644
--- a/editions/tw5.com/tiddlers/howtos/How to create a translation for TiddlyWiki.tid	
+++ b/editions/tw5.com/tiddlers/howtos/How to create a translation for TiddlyWiki.tid	
@@ -26,7 +26,7 @@ Quick and dirty instructions:
 # Run `./qbld.sh` to build TiddlyWiki
 # Open the TiddlyWiki file at `/MyTranslation/jermolene.github.com/index.html`
 # You should see your translation listed in the control panel, but the text of the translation will still be in British English
-# Edit the `.tid` and `.tids` files in your language folder to translate the English text
+# Edit the `.tid` and `.multids` files in your language folder to translate the English text
 
 Content of `plugin.info` for Joe Bloggs' Welsh translation:
 
diff --git a/languages/de-DE/ControlPanel.tids b/languages/de-DE/ControlPanel.multids
similarity index 100%
rename from languages/de-DE/ControlPanel.tids
rename to languages/de-DE/ControlPanel.multids
diff --git a/languages/de-DE/Docs/Fields.tids b/languages/de-DE/Docs/Fields.multids
similarity index 100%
rename from languages/de-DE/Docs/Fields.tids
rename to languages/de-DE/Docs/Fields.multids
diff --git a/languages/de-DE/Docs/ModuleTypes.tids b/languages/de-DE/Docs/ModuleTypes.multids
similarity index 100%
rename from languages/de-DE/Docs/ModuleTypes.tids
rename to languages/de-DE/Docs/ModuleTypes.multids
diff --git a/languages/de-DE/EditTemplate.tids b/languages/de-DE/EditTemplate.multids
similarity index 100%
rename from languages/de-DE/EditTemplate.tids
rename to languages/de-DE/EditTemplate.multids
diff --git a/languages/de-DE/Notifications.tids b/languages/de-DE/Notifications.multids
similarity index 100%
rename from languages/de-DE/Notifications.tids
rename to languages/de-DE/Notifications.multids
diff --git a/languages/de-DE/Search.tids b/languages/de-DE/Search.multids
similarity index 100%
rename from languages/de-DE/Search.tids
rename to languages/de-DE/Search.multids
diff --git a/languages/de-DE/SideBar.tids b/languages/de-DE/SideBar.multids
similarity index 100%
rename from languages/de-DE/SideBar.tids
rename to languages/de-DE/SideBar.multids
diff --git a/languages/de-DE/TiddlerInfo.tids b/languages/de-DE/TiddlerInfo.multids
similarity index 100%
rename from languages/de-DE/TiddlerInfo.tids
rename to languages/de-DE/TiddlerInfo.multids
diff --git a/languages/en-US/ControlPanel.tids b/languages/en-US/ControlPanel.multids
similarity index 100%
rename from languages/en-US/ControlPanel.tids
rename to languages/en-US/ControlPanel.multids
diff --git a/languages/fr-FR/ControlPanel.tids b/languages/fr-FR/ControlPanel.multids
similarity index 100%
rename from languages/fr-FR/ControlPanel.tids
rename to languages/fr-FR/ControlPanel.multids