Clarify quote_plus() usage.
diff --git a/Doc/library/urllib.rst b/Doc/library/urllib.rst
index 905c324..f6fe045 100644
--- a/Doc/library/urllib.rst
+++ b/Doc/library/urllib.rst
@@ -213,8 +213,9 @@
.. function:: quote_plus(string[, safe])
Like :func:`quote`, but also replaces spaces by plus signs, as required for
- quoting HTML form values. Plus signs in the original string are escaped unless
- they are included in *safe*. It also does not have *safe* default to ``'/'``.
+ quoting HTML form values when building up a query string to go into a URL.
+ Plus signs in the original string are escaped unless they are included in
+ *safe*. It also does not have *safe* default to ``'/'``.
.. function:: unquote(string)