While you can't italicize text when sending messages on an iPhone, you can italicize on an iPhone in Mail, Notes, and Pages.

Discord allows you to strikethrough text, as well as format your messages in bold, italics, or underlines. Here's how.

Formatting text on an app like Discord allows you to add emphasis to your written messages. For example, you can edit past messages to strikethrough anything that you want to take back. You can bold ...

You can use HTML elements to format text in various ways; for example: Bold text using <b>. Indicate strong importance, seriousness, or urgency using <strong ...