diff --git a/docs/Shell-Style-Guide.md b/docs/Shell-Style-Guide.md
index e4c10ded..d0cb0a40 100644
--- a/docs/Shell-Style-Guide.md
+++ b/docs/Shell-Style-Guide.md
@@ -94,6 +94,11 @@ if [[ "${my_var}" ]]; then
 fi
 ```
 
+### Changing user and group ownership of files
+
+Use `chown $user: [PATH]` instead of `chown $user:$user [PATH]` - the empty group parameter will cause chown to use the users login group. This resolves issues on systems where the user doesn't have their own group (eg. where all users are in a `users` group).
+
+
 ## Naming Conventions
 
 ### Function Names