>>On the second example, the style InformationTitle properly reads its CSS definition. The CSS definition tells that style to have a font-style normal.
>>
>>Why is this not working on the first example and why the space is a factor?
>>
>>Basically, as the style includes a font-style normal, I would expect the font-style to always be normal no matter is an italic tag has not been properly closed above.
>
>I'm not seeing that behaviour ("Speaking Experience" is in italic regardless of spacing) - what browser were you using?
>But, bottom line, the HTML is not valid and there is no defined behaviour for such a pattern so no 'right or wrong' browser rendering......

Exactly, the unclosed I tag is the reason I wouldn't bet on anything here. Any browser may decide to automatically close it on the next piece of markup, and have its own rules on what it considers one. Or it may not close it until end of paragraph (again, with its own rules as to what makes an end of paragraph).