[Jellby]

Originally Posted by cybmole

the Sony apparently completely ignores lines like <p class="whatever"><br /></p>

IS the epub spec ambiguous, or is Sony e-reader software out of lien with rest of world ?

All I can find is in the HTML 4 spec (which is inherited by XHTML and ePUB):

"User agents should ignore empty P elements."

and previously:

"authors should not rely on user agents to render white space immediately after a start tag or immediately before an end tag"

where "whitespace" means (in XHTML) any of:

SPACE (& #x0020;)
HORIZONTAL TABULATION (&#x0009;)
CARRIAGE RETURN (&#x000D;)
LINE FEED (&#x000A;)

Thus, <p>&nbsp;</p> is not empty, because &nbsp; is not whitespace and it's not ignored. And in my interpretation, <p><br/><p> is not empty either, but it seems the Adobe engine (used by the Sony reader) is removing the <br/> immediately preceding </p> (I think it was mentioned in another thread), so the paragraph becomes empty.

My advice, as expected is to convert all <p><br/><p> into an appropriate class for the following (or previous) paragraph.