diff --git a/Doc/library/stdtypes.rst b/Doc/library/stdtypes.rst
index af537aa..8cc3722 100644
--- a/Doc/library/stdtypes.rst
+++ b/Doc/library/stdtypes.rst
@@ -2058,6 +2058,10 @@
    that when in non-blocking mode, less data than what was requested may be
    returned, even if no *size* parameter was given.
 
+   .. note::
+      As this function depends of the underlying C function :cfunc:`fread`,
+      it resembles its behaviour in details like caching EOF and others.
+
 
 .. method:: file.readline([size])