[Adrian Schneider]

Say if it was a profile field...

PHP Code:

if ($vbulletin->userinfo['fieldX'] == 'Yes')
{
    $vbulletin->options['legacypostbit'] = 1;
}
else
{
    $vbulletin->options['legacypostbit']  = 0;
} 


Assuming that the profile field is a "Yes" or "No" field (case sensitive).

I'm not 100% sure where it checks the option and changes the output, but putting this in the hook I suggested would work, or look for the hack here (which does the same/very similar thing AFAIK).

To view all the options go into your ACP... vBulletin Options > vBulletin Options

or throw in this up in a php file...

PHP Code:

require_once('./global.php');

// check access
if (!is_member_of($vbulletin->userinfo, 6))
{
    print_no_permission();
}

// display array
echo '<pre>';
print_r($vbulletin->options);
echo '</pre>'; 


if you are still using 3.0.x change all occurances of
"$vbulletin->options" to "$vboptions"
and all
"$vbulletin->userinfo" to "$bbuserinfo"