on systems conforming to SUSv4

Author: vladak

intro.tex

@@ -66,6 +66,8 @@
 UNIX~V7.  Some versions of AIX, HP-UX and macOS on selected architectures
 are compliant with the previous version SUSv3
 (\url{http://www.opengroup.org/openbrand/register/xy.htm}).
+As of 2025, there is a single system registered with the UNIX V7 trademark, i.e.
+conforming to SUSv4, and that is AIX.
 \item The specific source code examples linked from this material are usually
 tested on Solaris, macOS and Linux.
 \end{itemize}