Update docs/reference/elasticsearch/command-line-tools/elasticsearch-keystore.md

Co-authored-by: Liam Thompson <[email protected]>

Author: mailahmeduk

docs/reference/elasticsearch/command-line-tools/elasticsearch-keystore.md

@@ -90,6 +90,10 @@ Only some settings are designed to be read from the keystore. However, there is
 
 ## Handling special characters
 
+:::{important}
+Improper handling of special characters can lead to authentication failures and service outages.
+:::
+
 Exclamation mark: `!`
 : When using the shell, the combination `\!` is stored as just `!`. This can lead to authentication failures if the password is not stored as intended.