Collapse-O-Matic version 1.7.7 has just been released. This update includes a new content filter feature. To demonstrate what exactly this does, below are two examples of the html from a simple collapse element. By default the content filter is turned off, but this can be set in the plugin options page under Dashboard > Settings > Collapse-O-Matic > Filter Content.

Without Filter

[expand title="Trigger"]This is a bit of content text[/expand]

<div id="target-id1820" class="collapseomatic_content">This is some special text to display about item one</div>

With Filter

[expand title="Trigger" filter="true"]
This is a bit of content text
[/expand]

<div id="target-id1820" class="collapseomatic_content"><p>This is some special text to display about item one</p>
</div>