#16333: document a way to get rid of trailing whitespace when indent is used.
diff --git a/Lib/json/encoder.py b/Lib/json/encoder.py
index 169450d..4d1aaa8 100644
--- a/Lib/json/encoder.py
+++ b/Lib/json/encoder.py
@@ -131,7 +131,10 @@
         If indent is a non-negative integer, then JSON array
         elements and object members will be pretty-printed with that
         indent level.  An indent level of 0 will only insert newlines.
-        None is the most compact representation.
+        None is the most compact representation.  Since the default
+        item separator is ', ',  the output might include trailing
+        whitespace when indent is specified.  You can use
+        separators=(',', ': ') to avoid this.
 
         If specified, separators should be a (item_separator, key_separator)
         tuple.  The default is (', ', ': ').  To get the most compact JSON