diff --git a/SC2181.md b/SC2181.md
index 3b04745..361a660 100644
--- a/SC2181.md
+++ b/SC2181.md
@@ -35,6 +35,8 @@ To check that a command returns success, use `if mycommand; then ...`.
 
 To check that a command returns failure, use `if ! mycommand; then ...`.
 
+To additionally capture output with command substitution: `if output=$(mycommand); then ...`
+
 This also applies to `while`/`until` loops.
 
 ### Exceptions: