--- a/_locales/en/messages.json	Tue Nov 27 16:05:14 2018 +0100
+++ b/_locales/en/messages.json	Fri Dec 07 23:00:41 2018 +0100
@@ -7,6 +7,14 @@
         "message": "Indicates available RSS and Atom feeds and renders previews.",
         "description": "Description of the extension."
     },
+    "feedReaderSelectionLabel": {
+        "message": "Subscribe to this feed using",
+        "description": "Label for the feed reader menu."
+    },
+    "subscribeButtonLabel": {
+        "message": "Subscribe Now",
+        "description": "Label for the subscibe button."
+    },
     "defaultFeedTitle": {
         "message": "Untitled Feed",
         "description": "Default title for feeds."
@@ -30,5 +38,57 @@
     "filesTitle": {
         "message": "Media Files:",
         "description": "Title of the list of media files."
+    },
+    "feedReadersTitle": {
+        "message": "Feed Readers",
+        "description": "Title of the feed reader options."
+    },
+    "feedReaderMoveUpButton": {
+        "message": "Move Up",
+        "description": "Label of the button for deleting a feed reader up."
+    },
+    "feedReaderMoveDownButton": {
+        "message": "Move Down",
+        "description": "Label of the button for moving a feed reader down."
+    },
+    "feedReaderRemoveButton": {
+        "message": "Remove",
+        "description": "Label of the button for deleting a feed reader."
+    },
+    "feedReaderAddButton": {
+        "message": "Add",
+        "description": "Label of the button for adding a feed reader."
+    },
+    "feedReaderTitleLabel": {
+        "message": "Title",
+        "description": "Label of the text input field for the feed reader title."
+    },
+    "feedReaderTitlePlaceholder": {
+        "message": "e.g. My Feed Reader",
+        "description": "Placeholder displayed in the text input field for the feed reader title."
+    },
+    "feedReaderUrlTemplateLabel": {
+        "message": "URL Template",
+        "description": "Label of the text input field for the feed reader URL template."
+    },
+    "feedReaderUrlTemplatePlaceholder": {
+        "message": "e.g. https://feedreader.example.org/?subscribe=%s",
+        "description": "Placeholder displayed in the text input field for the feed reader URL template."
+    },
+    "feedReaderUrlTemplateCaption": {
+        "message": "URL for subscribing to feeds with a placeholder %s which will be substituted with the feed URL.",
+        "description": "Caption for the the text input field for the feed reader URL template."
+    },
+    "invalidURLError": {
+        "message": "Please enter a valid URL.",
+        "description": "Error message if the subscription URL template is invalid."
+    },
+    "invalidProtocolError": {
+        "message": "Please enter a URL which uses either the HTTP or HTTPS protocol.",
+        "description": "Error message if the protocol of the subscription URL template is neither HTTP nor HTTPS."
+    },
+    "missingPlaceholderError": {
+        "message": "Please enter a subscription URL which contains a placeholder \"%s\" for the feed URL.",
+        "description": "Error message if the placholder is missing from the subscription URL template."
     }
 }