If Fault Lines are used to limit the approach to metal targets, they must be placed at least 26 feet from the targets so that the competitor may inadvertently fault the line and still be outside the 23 feet minimum distance (see Rule 10.5.17).
Yes, shooting a steel target closer than 23 feet in USPSA is a DQ. Nothing in the rulebook about 10 yards, although a club might say "10 yards" because that is usually implemented as "10 paces" and not everyone has a calibrated "pace", and 10 paces will probably exceed 26 feet.
Is 26 feet supposed to be the equivalent of eight meters?
For years, IDPA has had no minimum distance for steel, but they now have a minimum of ten yards.