I think you don't understand the intent. It's to help you give hints to the rendering engine about where you'd prefer to have line breaks if there needs to be one nearby, so that you can tweak some of your text so it reads better.

I'd be surprised if it broke your layout on a browser (aside from the fact it's not a standardized tag).

Ah, I see, you're right. Actually taking the time to read more of the referred to page on quirksmode.org does make the intent of the tag clearer. The quote taken out of context in the article does make the tag sound like rather ridiculous though.

More from quirksmode.org:

I use it a lot in the great compatibility tables. These tables are very large and very tight, and I wish to avoid horizontal scrollbars, if possible. These scrollbars are mainly caused by the length of method or attribute names, for instance getElementsByTagName(). Therefore I do:

<div class="name">getElements<wbr>ByTagName()</div>

I give the browser the option of adding a line break. This won't be necessary on very large resolutions, when the table has plenty of space. On smaller resolutions, however, such strategically placed line breaks keep the table from growing larger than the window, and thus causing horizontal scrollbars.

I still won't be using it. :)