Created SC1037 (markdown)

SC1037.md

@@ -0,0 +1,21 @@
+## Without braces, this is $1 plus a literal. Use ${10} instead. 
+
+### Problematic code:
+
+    echo "Ninth parameter: $9"
+    echo "Tenth parameter: $10"
+
+### Correct code:
+
+    echo "Ninth parameter: $9"
+    echo "Tenth parameter: ${10}"
+
+### Rationale:
+
+For legacy reasons, `$10` is interpreted as the variable `$1` followed by the literal string `0`.
+
+Curly braces are needed to tell the shell that both digits are part of the parameter expansion.
+
+### Contraindications
+
+If you wanted the trailing digits to be literal, `${1}0` will make this clear to both humans and shellcheck.