[Andreas]

Editing/Deleting posts made by other users is a moderator permission, therefore you will not find this as a usergroup permission.
You would have to give all users of this group moderator permissions for this forum.

To achieve this you can put the following code in template phpinclude_start:

PHP Code:

if (is_member_of($bbuserinfo, X))
{
  $imodcache[Y][$bbuserinfo['userid']]['permissions'] = 3;
} 


X must be replaced with the usergroup ID, Y must be replaced with the forum id.