Blogger Extensions:

<convertLineBreaks> — Line Break status. This flag, when set to true, means that a blog's posts will have their newlines automatically converted to <br />. If set to false, newlines will not be transformed. This flag is read-only and can only be changed through the Blogger web interface for now. You can see a blog's Line Break status by sending a GET to it's service.feed URI and looking for it as a child of the <feed> element:

<convertLineBreaks xmlns="http://www.blogger.com/atom/ns#">true</convertLineBreaks>