content: normal | none | [ <string> |  <url> | 
     counter(<identifier> [, style]?) | counters( <identifier>, string [, style]?) 
     attr(<identifier>) | open-quote | close-quote | no-open-quote | no-close-quote ]+

• Allows content not in the original document to be displayed
• An example already is <ol> and <ul> producing numbers or bullets
• Every element has a pseudo-element :before and :after which can be used to add content before and after an element

div.ul {margin-left:5pt;border:solid red 2pt;padding:6pt;background-color:white}
div.li:before {content:"*"; color:green;font-size:16pt;margin-left:5pt;}

<div class="ul">
  <div class="li">First list item</div>
  <div class="li">Second list item</div>
  <div class="li">Third list item</div>
</div>

Produces: