Formatting text

Text files cannot contain formatting.

What that means is that the formatting is not encoded in the file: only the characters are.

This doesn’t mean that you can’t express formatting within the text file. For example, Markdown is a common way of formatting text: you put an underscore either side of a word to indicate it is italic, or a couple of asterisks to show it is bold.

This is an _italic_ word and this is
a **bold** word in a Markdown file.

But this is still a text file because it only contains characters (the _ and the * are just characters in the text). The formatting only gets applied if you view the file in a program which interprets the file, and displays the results.

Similarly, you can express italic and bold in HTML using the tags <em> (emphasis) and <strong>:

This is an <em>italic</em> word and this is a
<strong>bold</strong> word in an HTML file

The formatting there is not encoded in the file: it only contains characters which in this case include the symbols <, >, and /. You only see italic and bold if you look at the contents of a file using a program that displays it after processing it: for example, a web browser.