Backport r54763: repair missing spaces after \UNIX.
diff --git a/Doc/mac/using.tex b/Doc/mac/using.tex
index b21a98e..bf3174d 100644
--- a/Doc/mac/using.tex
+++ b/Doc/mac/using.tex
@@ -2,7 +2,7 @@
\sectionauthor{Bob Savage}{bobsavage@mac.com}
Python on a Macintosh running Mac OS X is in principle very similar to
-Python on any other \UNIX platform, but there are a number of additional
+Python on any other \UNIX{} platform, but there are a number of additional
features such as the IDE and the Package Manager that are worth pointing out.
Python on Mac OS 9 or earlier can be quite different from Python on