When doing a Check Design on a pcb, under Manufacturing (under Tools -> Design Rule Check) the error "Track too wide to backoff from drill" shows up an any pads or vias where the trace is wide and so would cover the actual hole. Obviously if one is manually drilling a PCB, i.e. where CNC is not used, then if the track is so wide that it actually covers the hole, then it becomes difficult to precisely locate the hole center for drilling. However, no manufacturer of PCBs will back off traces so that mathematically, the trace does not cover the hole. Yet DesignSpark has the option "Drill Back" in its list of manufacturing checks. Here's a link that also mentions this particular error, and that about board manufacturers would not pull back traces so that they do not cover the annular ring of a pad or via: http://pididu.com/wordpress/blog/ignore-pcb-layout-drill-back-off-warnings/
Please enlighten me if my assumption is in error but therefore, why does DesignSpark continue to include this particular manufacturing check when it is for all intents and purposes "obsolete" and only serves to produce an almost endless list of errors that should be ignored ?