diff --git a/SC2002.md b/SC2002.md
index 3161a71..84c9587 100644
--- a/SC2002.md
+++ b/SC2002.md
@@ -1,5 +1,9 @@
 # Useless cat. Consider `cmd < file | ..` or `cmd file | ..` instead.
 
+This suggestion was enabled by default up to and including ShellCheck 0.10.0.
+
+In later versions, it is [[optional]]. It must be explicitly enabled with a [[directive]] `enable=useless-use-of-cat` in a `# shellcheck` comment or `.shellcheckrc`
+
 ### Problematic code:
 
 ```sh