Using bigger fonts help draw attention to important text, such as headers, keywords or lists. Although you could previously use the HTML attribute Font to designate a specific size, Craigslist no longer allows this attribute for sale or housing listings. Instead, use the Big attribute for use in any section.
Adding the Big Attribute
The Posting Body section of Craigslist's posting form automatically recognizes and translates certain HTML attributes. To enlarge certain text, place "<big>" (without quotes here and throughout) before the text and "</big>" after the text. You can also nest additional Big attributes to create even larger fonts. As an example, "This <big><big><big>is</big></big></big> a test" will make "is" very large while keeping the other text the normal size.