I have a regex that is designed to help improve readability for a html document.
Code:
"(?=((?!<\/?em).)*<\/em>)
The purpose of this regex is to escape " marks from within <EM> affected sentences. Example:

Before: <P>This "is" <EM>a <STRONG>"Test "</STRONG></EM></P>
After: <P>This "is" <EM>a <STRONG></EM>"<EM>Test</EM>"<EM></STRONG></EM></P>...