Pseudo-classes ::after

The ::after pseudo-element can be used to describe generated content after an element's content.

Syntax

selector::after{ preperties }

When the ::first-letter and ::first-line pseudo-elements are applied to an element having content generated using ::after, it applies to the first letter or line of the element including the generated content.

[style.css]

 p:after{
   content: "  :Note";
 }

[index.html]

<body>
  <p>In CSS 2.1, it is not possible to refer to attribute values 
     for other elements than the subject of the selector.</p>
</body>

The CSS Selectors Level 3 specification defines the ::after pseudo-element in 7.4. The ::before and ::after pseudo-elements. And see also