Consistently use \POSIX{} to denote POSIX. There were at least two different
ways to do it previously (not counting module names).
diff --git a/Doc/lib/libunix.tex b/Doc/lib/libunix.tex
index 05db4a9..9e1ea53 100644
--- a/Doc/lib/libunix.tex
+++ b/Doc/lib/libunix.tex
@@ -7,10 +7,10 @@
\begin{description}
\item[posix]
---- The most common Posix system calls (normally used via module \code{os}).
+--- The most common \POSIX{} system calls (normally used via module \code{os}).
\item[posixpath]
---- Common Posix pathname manipulations (normally used via \code{os.path}).
+--- Common \POSIX{} pathname manipulations (normally used via \code{os.path}).
\item[pwd]
--- The password database (\code{getpwnam()} and friends).
@@ -28,7 +28,7 @@
--- GNU's reinterpretation of dbm.
\item[termios]
---- Posix style tty control.
+--- \POSIX{} style tty control.
\item[TERMIOS]
--- The symbolic constants required to use the \code{termios} module.