Edit the STANDARD_ERROR template and add what you want.
This is the area of code to look at:
Code:
<div class="smallfont">$vbphrase[not_logged_no_permission]</div>
<ol>
<li class="smallfont">$vbphrase[not_logged_in_fill_in_form]</li>
<li class="smallfont">$vbphrase[may_not_have_sufficient_privileges]</li>
<li class="smallfont">$vbphrase[administrator_may_disabled_account]</li>
</ol>
You can either add more options or create more phrases and add them.