The SCLogin module is doing it the Joomla-recommended way. We allow Joomla to automatically add the moduleclass suffix when the template requests for it to do so.
The Search Module (and the mod_menu) break Joomla's own conventions and includes the class suffix inside the layout file itself. This means that if you were to place it in position-7, there would actually be 2 divs with the class suffix on it. While that may work on your site, it would cause multiple issues on many other sites, so we don't specifically include the class suffix inside our layout file.
The search and menu modules do this, as best as I can tell, because they are often placed in these containerless divs like position-0 on your site.
Joomla's own login module, mod_login does *not* add the class suffix. The same is true for every other core module, as far as I know. We go by the standards Joomla sets to prevent conflicts on the vast majority of sites.
With all that said, if you'd like to force the class suffix so that it will always show at least once, you can follow our
SCLogin theme guide
to create a template override. Then, you just need to add a surrounding div to the entire output, like:
<div class="mod_sclogin<?php echo $moduleclass_sfx ?>">
... all our code...
</div>
I hope that helps explain,
Alex
SCLogin Module Class Suffix Ignored?
