CSS - Element
Most CSS style sheet rules use the names of elements to specify how the elements (HTML, XML, …) should be rendered.
A replace element has its content outside the scope of the CSS formatting model, such as:
- an image,
- embedded document,
- or applet.
For example, the content of the HTML IMG element is often replaced by the image that its “src” attribute designates. Replaced elements often have intrinsic dimensions:
- an intrinsic width,
- an intrinsic height,
- and an intrinsic ratio.
For example, a bitmap image has an intrinsic width and an intrinsic height specified in absolute units (from which the intrinsic ratio can obviously be determined). On the other hand, other documents may not have any intrinsic dimensions (for example, a blank HTML document).
User agents may consider a replaced element to not have any intrinsic dimensions if it is believed that those dimensions could leak sensitive information to a third party. For example, if an HTML document changed intrinsic size depending on the user's bank balance, then the UA might want to act as if that resource had no intrinsic dimensions.
The content of replaced elements is not considered in the CSS rendering model.