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+## Scripts are case sensitive. Use 'if', not 'If'.
+
+### Problematic code:
+
+    If true
+    Then 
+      echo "hello"
+    Fi
+
+### Correct code:
+
+    if true
+    then
+      echo "hello"
+    fi
+
+### Rationale:
+
+Shells are case sensitive and do not accept `If` or `IF` in place of lowercase `if`.
+
+### Contraindications
+
+If you're aware of this and insist on naming a function `WHILE`, you can quote the name to prevent shellcheck from thinking you meant `while`.
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