setvbuf documentation

[markjynx@...]

In the manual, it says setvbuf "sets the buffering mode mode for an 
output file".
I believe it's a bit misleading.
The C standard specifies that setvbuf causes changes in input/output 
buffering, not just output.
Thus input files, such as stdin, will also be affected.
Am I mistaken, or should I send a manual patch?