hook_tabitha.php

<?php

function hook_tabitha(&$hook)
{
	global $db, $template, $user;

	if (empty($template->_tpldata['postrow']))
	{
		return;
	}

	// Founders can always warn
	if ($user->data['user_type'] == USER_FOUNDER)
	{
		return;
	}

	// First loop throught the template rows and create a map that links
	// the "postrow" to the ID of the actual poster
	$postrow_posterid = array();
	foreach ($template->_tpldata['postrow'] as $row => $data)
	{
		$postrow_posterid[$row] = $data['POSTER_ID'];
	}

	// Now we know the user ids, select their `group_warn` status
	$userid_groupwarn = array();
	$sql_array = array(
		'SELECT'        => 'g.group_id, g.group_warn, u.user_id, u.group_id',
		'FROM'          => array(
			USERS_TABLE     => 'u',
		),
		'LEFT_JOIN'     => array(
			array(
				'FROM'  => array(GROUPS_TABLE => 'g'),
				'ON'    => 'g.group_id = u.group_id'
			),
		),
		'WHERE'         => $db->sql_in_set('u.user_id', $postrow_posterid),
	);
	$sql	= $db->sql_build_query('SELECT', $sql_array);
	$result	= $db->sql_query($sql);
	while ($row = $db->sql_fetchrow($result))
	{
		$userid_groupwarn[$row['user_id']] = $row['group_warn'];
	}
	$db->sql_freeresult($result);

	// At this point we've got all information we need, loop once again through
	// the `postrow` and inject a new template variable into the row.
	// This variable will be accessable through `postrow.S_GROUP_WARN`
	foreach ($postrow_posterid as $row => $id)
	{
		if (!$userid_groupwarn[$id])
		{
			// Alterblock array love ^^
			$template->alter_block_array('postrow', array(
				'U_WARN'	=> false,
			), $row, 'change');
		}
	}
}

$phpbb_hook->register(array('template', 'display'), 'hook_tabitha');

hook_tabitha_mcp.php

<?php

function hook_tabitha_mcp(&$hook)
{
	global $db, $module, $user;

	// Skip founders always
	if ($user->data['user_type'] == USER_FOUNDER)
	{
		return;
	}

	// No Module, certainly no MCP
	if (!isset($module) || ($module instanceof p_master) === false)
	{
		return;
	}

	// No MCP
	if ($module->p_class != 'mcp')
	{
		return;
	}

	// Make sure that we're either on the warning or banning tab
	if ($module->p_name != 'warn' && $module->p_name != 'ban')
	{
		return;
	}

	// When bansubmitting
	if ((isset($_REQUEST['bansubmit']) && $module->p_mode == 'user') || ($module->p_mode == 'warn_user' && isset($_REQUEST['action']['add_warning']) && $_REQUEST['action']['add_warning'] == 'Submit'))
	{
		// See if the user is part of a non ban group
		if (isset($_REQUEST['bansubmit']))
		{
			$ban = utf8_normalize_nfc(request_var('ban', '', true));
			$list = array_unique(explode("\n", $ban));
			array_walk($list, 'utf8_clean_string');

			$sql = 'SELECT u.username, g.group_ban
				FROM (' . USERS_TABLE . ' u, ' . GROUPS_TABLE . ' g)
				WHERE ' . $db->sql_in_set('u.username_clean', $list) . '
					AND g.group_id = u.group_id';
		}
		else
		{
			$user_id = request_var('u', 0);
			$sql = 'SELECT u.username, g.group_ban
				FROM (' . USERS_TABLE . ' u, ' . GROUPS_TABLE . " g)
				WHERE u.user_id = {$user_id}
					AND g.group_id = u.group_id";
		}

		$result	= $db->sql_query($sql);
		$gbs	= $db->sql_fetchrowset($result);
		$db->sql_freeresult($result);

		// See whether there is a user in the ban list that can't be banned
		foreach ($gbs as $gb)
		{
			if ($gb['group_ban'] == 0)
			{
				trigger_error("Can't ban: {$gb['username']}", E_USER_ERROR);
			}
		}
	}
}

// Need this hook to be executed *before* the module code
$phpbb_hook->register(array('template', 'display'), 'hook_tabitha_mcp');

hook_tabitha?

Yez, its for /me super sekredt tabitha project ;)