Bold, italic and strikethrough: WhatsApp formatting
Native formatting is quick to learn. For bold, put an asterisk before and after the word. For italic use underscores, for strikethrough use tildes. You get a typewriter font (monospace) with three backticks before and after the text.
The important thing is that there is no space between the marker and the word. When sent, the markers disappear and the text appears formatted. This method is ideal for messages because it looks clean and is guaranteed to display correctly for the recipient.