Fix the doc for PIPE_BUF
diff --git a/Doc/library/select.rst b/Doc/library/select.rst
index 6730910..4804b1e 100644
--- a/Doc/library/select.rst
+++ b/Doc/library/select.rst
@@ -96,9 +96,11 @@
.. attribute:: select.PIPE_BUF
- Files reported as ready for writing by :func:`select`, :func:`poll` or
- similar interfaces in this module are guaranteed to not block on a write
- of up to :const:`PIPE_BUF` bytes.
+ The minimum number of bytes which can be written without blocking to a pipe
+ when the pipe has been reported as ready for writing by :func:`select`,
+ :func:`poll` or another interface in this module. This doesn't apply
+ to other kind of file-like objects such as sockets.
+
This value is guaranteed by POSIX to be at least 512. Availability: Unix.
.. versionadded:: 3.2