<WBR> | NN all IE all HTML n/a
<WBR> | End Tag: Forbidden
If you use the NOBR element to define content that should have no word wrapping or line breaks, you can use the WBR element to advise the browser that it can break up the content if the width of the browser window requires it. The locations of these provisional breaks are marked in the source code with the WBR element. In a sense, the NOBR and WBR elements give the author control over word wrapping of running content. Neither element is included in the HTML specification but have been long a part of both browsers' HTML vocabulary.
Example
    <NOBR>This is a long line of text that could run on and on, <WBR>forcing the browser to display the horizontal scrollbar after awhile.</NOBR>
Object Model Reference
IE | [window.]document.all.elementID