Lots of small corrections by Andrew Kuchling (plus all new rotor docs)
diff --git a/Doc/libfcntl.tex b/Doc/libfcntl.tex
index dd5212b..e361d5e 100644
--- a/Doc/libfcntl.tex
+++ b/Doc/libfcntl.tex
@@ -13,12 +13,12 @@
\renewcommand{\indexsubitem}{(in module struct)}
-\begin{funcdesc}{fcntl}{fd\, op\, arg}
+\begin{funcdesc}{fcntl}{fd\, op\optional{\, arg}}
Perform the requested operation on file descriptor \code{\var{fd}}.
The operation is defined by \code{\var{op}} and is operating system
dependent. Typically these codes can be retrieved from the library
- module \code{FCNTL}. The argument \code{\var{arg}} is optional. When
- it is missing it is interpreted as the integer value \code{0}. When
+ module \code{FCNTL}. The argument \code{\var{arg}} is optional, and
+ defaults to the integer value \code{0}. When
it is present, it can either be an integer value, or a string. With
the argument missing or an integer value, the return value of this
function is the integer return value of the real \code{fcntl()}