clarify buffer arg #7178
diff --git a/Doc/library/io.rst b/Doc/library/io.rst
index a85e924..3308639 100644
--- a/Doc/library/io.rst
+++ b/Doc/library/io.rst
@@ -108,8 +108,8 @@
*buffering* is an optional integer used to set the buffering policy. By
default full buffering is on. Pass 0 to switch buffering off (only allowed
- in binary mode), 1 to set line buffering, and an integer > 1 for full
- buffering.
+ in binary mode), 1 to set line buffering, and an integer > 1 to indicate the
+ size of the buffer.
*encoding* is the name of the encoding used to decode or encode the file.
This should only be used in text mode. The default encoding is platform