diff --git a/Comments:BIP-0039.md b/Comments:BIP-0039.md
index dff857a..af25c91 100644
--- a/Comments:BIP-0039.md
+++ b/Comments:BIP-0039.md
@@ -32,4 +32,7 @@ There are alternative binary-to-word encodings, e.g. PGP word list (a.k.a biomet
 Are there any benefits of SHA-256-derived checksum requirement? User ends up in the same situation if they input incorrect words - irrespectively of the checksum appended. Typing errors are not prevented. --Greg Tonoski, 2023-09-13
 
 # Separation of concerns: key generation technique
-Key generation techniques may vary and co-exist. They are not dependent on Bitcoin protocol and vice-versa. While there are benefits of interoperability (e.g. standardized format of keys), the key generation techniques (e.g. PBKDF2, "The iteration count is set to 2048", source of randomness) may be treated separately and individually.
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+Key generation techniques may vary and co-exist. They are not dependent on Bitcoin protocol and vice-versa. While there are benefits of interoperability (e.g. standardized format of keys), the key generation techniques (e.g. PBKDF2, "The iteration count is set to 2048", source of randomness) may be treated separately and individually.
+
+# Robustness: POSIX shell reserved words are used in the BIP39 wordlist
+Shells may interpret some words as reserved ones if not quoted, e.g. time, then, select, until.
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