CSS2 Pseudo Elements and RH7

[Cynic Librarian]

I am trying to have text generated and added automatically to content in
RH7.

For example, with CSS2, I can supposedly include in my RH7 style sheet the
"x:after {content: 'foobu:'}" pseudo element command and have this text
added every time the x style appears in my topic. That is, every time style
x appears, I would get the following generated content before any text with
style x: foobu: .

In another example, I could define body so that the words, "the End" appears
after all body text:

body:after {
                 display: block;
                 content: "The End";
}

This does not seem to work in RH7. Has anyone used pseudo elements? I'd
appreciate any guidance on this issue.

Thanks