The keyword you've selected can't be found in Visual Basic Help. It's possible that:
The easiest way to get help on a specific keyword is to position the insertion point anywhere within the keyword you want help on and press F1. You do not need to select the keyword. In fact, if you select only a portion of the keyword, or more than a single word, Help will not find what you're looking for.
To use the built-in Help search dialog box, press the Help Topics button on the toolbar.
One option to possibly find what you're looking for is to view the ReadMe file that comes with Visual Basic. This document contains information regarding last-minute changes, additions, and deletions that did not make it into the final documentation.