diff --git a/devdocs/specs/core-internationalization.txt b/devdocs/specs/core-internationalization.txt
index d20539b6..73892a8b 100644
--- a/devdocs/specs/core-internationalization.txt
+++ b/devdocs/specs/core-internationalization.txt
@@ -9,4 +9,7 @@ REQUIREMENTS
     - API data is in as neutral a format as possible, i.e. ISO whatever it is for dates and times, currency is just a number? (not going multicurrency?)
 
     CALENDARS
-    - Only the Gregorian calendar is supported
\ No newline at end of file
+    - Only the Gregorian calendar is supported
+
+    USEFUL INFO
+    https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DateTimeFormat
\ No newline at end of file