diff --git a/SC2230.md b/SC2230.md
index 3e9be5d..068e6be 100644
--- a/SC2230.md
+++ b/SC2230.md
@@ -1,5 +1,7 @@
 ## which is non-standard. Use builtin 'command -v' instead.
 
+Note: This check is opt-in only in ShellCheck 0.7.1+ (`shellcheck -o deprecate-which`).
+
 ### Problematic code:
 
 ```sh
@@ -18,7 +20,7 @@ command -v grep
 
 ### Exceptions:
 
-None
+This check is opt-in only in 0.7.1+, and you may choose to [[ignore it]] in earlier versions. `which` is very common, and some prefer its executable-or-nothing behavior over `command -v`'s handling of builtins, functions and aliases.
 
 ### Caveats: