When writing a code review suggestion on GitHub, the suggestion block normally opens with a triple-backtick fence:

~~~
```suggestion
...
```
~~~

If the code you are suggesting itself contains triple backticks (e.g. a Markdown snippet), the inner fences break the outer suggestion block. The fix is to use triple tildes for the outer fence instead:

````
~~~suggestion
```bash
echo "hello"
```
~~~
````

GitHub's Markdown parser treats `~~~` and ```` ``` ```` as equivalent fencing delimiters, so `~~~suggestion` is recognised as a valid suggestion block while leaving any inner triple-backtick fences unambiguous.