"Signature" does not look like in design patterns

This HTML-code is in design for user's signature:

<div class="signature">
-------------------------
<br />
Text of signature
</div>

This HTML-code is in realisation for user's signature:

<p class="forum_message_cell_signature">
Text of signature
</p>

in pattern master.css class SIGNATURE is defined as

.post_details, .signature {
	width: 100%;
	padding: 5px;
	border-bottom: 1px solid #b2b2b2;
	font-size: 11px;
}
.signature {
	margin-top: 10px;
	border-bottom: none;
	color: #8e8e8e;

in deployed master.css I couldn't find nor class SIGNATURE, nor class FORUM_MESSAGE_CELL_SIGNATURE.

Foe example, http://deploy.jtalks.org/jcommune/topics/35?page=3 text of post and text of signature are divided only by spaces and CRs. It's hard to understand where is post ends and signature starts.