For questions and problems with the CMS core. This board is NOT for any 3rd party modules, addons, PHP scripts or anything NOT distributed with the CMS made simple package itself.
hr is used a lot in default templates to "cut" the flow of the page. the reason for using hr is that text based clients show it well and understand it better than ( or something similar). Also screenreaders understand it well.
and for that reason was added to have similar effect for graphical browsers.
but as always, you can edit the templates and css as you wish...
I personally use it as "hr class="accessibility" and my own hr's seperately, as divs, though I'd rather use real hr.
It's rough because I'd like to use the HR tag, but most designers are not happy with it's output.... so I usually have to create divs, and just name them well, so they are clearly used as page dividers.
In all honesty, HR doesn't carry any meaning for me natively, it's only my knowledge as a web developer that gives it meaning. I know it stands for horizontal rule, but seriously, abbreviations are not semantically very solid. That's why I don't think it's too bad to use a div and name it class="horizontalRule"