This semantic template is for page descriptions. Unlike the other semantic data templates, as well as adding the property it also produces a visual output (as long as the TEXT parameter is non-empty), displaying it in a left-justified block of italic text with gold border and light gold background. It has just the one parameter which is the description (500 characters or less). If the description is 500 characters or longer, the excess is displayed in red, and the page is assigned to Category:Pages with overlong descriptions
It is for use by other templates rather than directly in pages.
The result will be as shown below with your text replacing the curly-braced parameter.