Hi!

I know that it's clearly invalid when you place a block element inside an inline element (it's generate sometimes strange results in browsers). But is it valid to set an inline element display property to block inside an other - inline containing - element?

i.e.:
<span>
<em style="display: block">some box</em>
Lorem ipsum dolor sit amet, consectetur adipiscing elit.
</span>

i.e. 2. :
<span>
<em style="float: left; width: 100px;">some box</em>
Lorem ipsum dolor sit amet, consectetur adipiscing elit.
</span>

I know that it's valid to place an inline-block element inside an inline element (is it?), but what about the other relationships? I can't find any table or explanation of this problem in the CSS spec.

The spec said (through an example), that inside a <p> tag we can float elements: http://www.w3.org/TR/CSS21/visuren.html#comp-float.
If we float an element, the display property computed value is block (http://www.w3.org/TR/CSS21/visuren.html#dis-pos-flo). The HTML dtd said that we can't place a block element inside a <p> tag. So now what? Is it valid to place a "display: block" inline element inside an other inline element?

Thanks,
Andras