Retired Documentation: You are using the documentation for version 1.7.3 which was retired in 2013. Go here for the latest version documentation or check here for your available upgrades to the latest version.
Forum Update Notes for Version 1.1
Perform this step ONLY if you have Customized Your Forum Themes
You will need to manually add one new preference item to your profile area. In your control panel, go to:
Modules > Discussion Forum > Templates > Default > Member Profile Templates > Edit Preferences Form
Add the following code where you wish the preference to appear:
</tr><tr>
<td class='tableCellOne' colspan='2'>
<div class='defaultBold'><input type='checkbox' name='accept_messages' value='y' {state:accept_messages} /> {lang:accept_messages}
</div>
</td>