To italicize text in a Messenger conversation, simply add an underscore before and after the text you enter.
For example: : _italic_
To emphasize a specific part of your message in Messenger, you can put it in bold by adding a star before and after the text.
For example, you can do this by adding a star before and after the text: *bold*
You can also cross out your text in Messenger by adding a tilde (~) before and after the entered text. To do this, on Windows, use the key combination Alt Gr + 2.
Example : ~barred~
Facebook Messenger also allows you to write your messages using a monospace font. To do this, put the text of your message between two low accents (`), using the key combination Alt Gr + 7. You will have to press another key, Space for example, to validate the insertion of the accent.
Example : `text in monospace font`.
Should you need to insert a block of code into your conversation, Facebook Messenger will allow you to do so easily. To do so, you will need to add three bass accents before (Alt Gr + 7), make a line break (Shift + Enter), insert your code, add a line break again (Shift + Enter) and, finally, finish by inserting three bass accents again (Alt Gr + 7).
For example: :
<?php echo 'Hello World!
Since the use of these special characters for text formatting in Messenger Web is only functional from a PC, the messages and characters inserted before and after will be visible as they are from the Messenger mobile application.