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/libppath.tex b/Doc/libppath.tex
index 01f05a1..5298012 100644
--- a/Doc/libppath.tex
+++ b/Doc/libppath.tex
@@ -2,7 +2,7 @@
\label{module-posixpath}
\stmodindex{posixpath}
-This module implements some useful functions on POSIX pathnames.
+This module implements some useful functions on \POSIX{} pathnames.
\strong{Do not import this module directly.} Instead, import the
module \code{os} and use \code{os.path}.
@@ -78,7 +78,7 @@
function checks whether \var{p}'s parent, \file{\var{p}/..}, is on a
different device than \var{p}, or whether \file{\var{p}/..} and
\var{p} point to the same i-node on the same device --- this should
-detect mount points for all \UNIX{} and POSIX variants.
+detect mount points for all \UNIX{} and \POSIX{} variants.
\end{funcdesc}
\begin{funcdesc}{join}{p\optional{\, q\optional{\, ...}}}