diff --git a/SC2089.md b/SC2089.md
index 5edac7b..110900c 100644
--- a/SC2089.md
+++ b/SC2089.md
@@ -76,7 +76,14 @@ Then you can use `touch "'; rm -rf \$'\x2F'; '.txt"`  (or someone can trick you
 
 ### Exceptions
 
-Few and far between.
+Few and far between, such as, prompt variables. This from `man bash` "PROMPTING": 
+
+>       After the string is decoded, it is expanded via parameter expansion, command
+>       substitution, arithmetic expansion, and quote removal, subject to the value of the promptvars shell
+>       option (see the description of the shopt command under SHELL BUILTIN COMMANDS below).  This can have
+>       unwanted side effects if escaped portions of the string appear within command substitution or contain
+>       characters special to word expansion.
+>
 
 ### Additional resources