Text surrounded by asterisks (*) or underscores (_) are translated into italics.
Enclosed text with two asterisks (**) or two underscores(__) is translated into boldface.
In addition to the toolbar, you can create a strikethrough by adding "~~" around the desired text.
Example
This is *italics*.
This is _italics_.
This is **bold**.
This is __bold__.
This is ~~Strikethrough~~.
Result
Note: Your project will only use Markdown if specified by your administrator under Project Settings. To learn more about this, please read the Formatting Rules.