diff --git a/README.adoc b/README.adoc
index d6eb690..95211ad 100644
--- a/README.adoc
+++ b/README.adoc
@@ -15130,6 +15130,16 @@ Tests under link:userland/libs[] require certain optional libraries to be instal
 
 See for example <<blas>>.
 
+=== Userland content filename conventions
+
+The following basenames should always refer to programs that do the same thing, but in different languages:
+
+* `count`: count to infinity, sleep one second between each number
+** link:rootfs_overlay/lkmc/count.sh[]
+** link:rootfs_overlay/lkmc/python/count.py[]
+** link:userland/cpp/count.cpp[]
+** link:userland/posix/count.c[]
+
 === Userland content bibliography
 
 * The Linux Programming Interface by Michael Kerrisk https://www.amazon.co.uk/Linux-Programming-Interface-System-Handbook/dp/1593272200 Lots of open source POSIX examples: https://github.com/cirosantilli/linux-programming-interface-kerrisk