Created SC2028 (markdown)

SC2028.md

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+# echo won't expand escape sequences. Consider printf. 
+
+### Problematic code:
+
+    echo "Name:\t$value"
+
+### Correct code:
+
+    printf "Name:\t%s\n" "$value"
+
+### Rationale:
+
+Backslash escapes like `\t` and `\n` are not expanded by echo, and become literal backslash-t, backslash-n. 
+
+`printf` does expand these sequences, and should be used instead.
+
+Other, non-portable methods include `echo -e '\t'` and `echo $'\t'`. ShellCheck will warn if this is used in a script with shebang `#!/bin/sh`.
+
+If you actually wanted a literal backslash-t, use 
+
+    echo "\\t"
+
+### Contraindications
+
+None