Created SC1109 (markdown)

SC1109.md

@@ -0,0 +1,25 @@
+## This is an unquoted HTML entity. Replace with corresponding character.
+
+### Problematic code:
+
+```sh
+foo && bar
+```
+
+### Correct code:
+
+```sh
+foo && bar
+```
+
+### Rationale:
+
+There is an unquoted HTML entity, such as `&amp;`, `&gt;` or `&lt;` (instead of `&`, `>` and `<`) in your code. This usually happens when copy-pasting from a web site that has mismanaged its code formatting.
+
+You should go through the entire script and replace HTML entities with their corresponding characters. 
+
+Don't rely on ShellCheck to detect all of them. ShellCheck only warns about certain cases in certain contexts, while this issue tends to affect the entire script.
+
+### Exceptions:
+
+If you want to run a command called `amp` after backgrounding another command, add a space: `foo & amp;`.