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/libnntplib.tex b/Doc/libnntplib.tex
index b721efb..c2d470a 100644
--- a/Doc/libnntplib.tex
+++ b/Doc/libnntplib.tex
@@ -32,7 +32,7 @@
3798 Re: a few questions about the Mac implementation
3799 Re: PROPOSAL: A Generic Python Object Interface for Python C Modules
3802 Re: executable python scripts
-3803 Re: POSIX wait and SIGCHLD
+3803 Re: \POSIX{} wait and SIGCHLD
>>> s.quit()
'205 news.cwi.nl closing connection. Goodbye.'
>>>