This property automatically generates content to attach before/after a CSS selector (using the :before and :after pseudo-elements.) One or more keywords may be specified for this property, but the content does not actually exist in the document tree; it is generated "on-the-fly." The 'display' property is used with this property to specify the type of rendering box for the generated content.
Explicitly sets the value of this property to that of the parent.
Sets the content to nothing
Sets the content, if specified, to normal, which default is "none" (which is nothing)
Sets the content as a counter
Sets the content as one of the selector's attribute
Sets the content to the text you specify
Removes the opening quote from the content, if specified
Removes the closing quote from the content, if specified
Sets the content to be an opening quote
Sets the content to be a closing quote
Sets the content to be some kind of media (an image, a sound, a video, etc.)