Nothing is rendered when the following CSS is applied: img:before, img:after { content: " foo! "; } I would expect to get " foo! [image] foo! ".
It's not defined yet. See the note in section 12.1 in CSS2.1. "Note. This specification does not fully define the interaction of :before and :after with replaced elements (such as IMG in HTML). This will be defined in more detail in a future specification." Can't implement the behavior until we know what should happen.
P5 is not used for WebKit bugs. [http://webkit.org/quality/bugpriorities.html]
The WG discussed this at length, and decided that this should not be supported. Closing as WONTFIX. https://github.com/w3c/csswg-drafts/issues/625