diff --git a/SC2183.md b/SC2183.md
index d3903bc..ab1b355 100644
--- a/SC2183.md
+++ b/SC2183.md
@@ -21,4 +21,4 @@ Either remove the unused variables from the format string, or add enough argumen
 
 ### Exceptions:
 
-None.
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+When using the Ksh/Bash `%T` timestamp extension, such as `printf '%(%s)T\n'`, an argument of `-1` and no argument are both taken to mean the current time. In these cases, consider specifying `-1` explicitly.
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