What do NFPA 70 and AS/NZS 3000 have in common? The former is National Electrical Code (U.S.) and the later is the Wiring Rules (Australia and New Zealand). Both are electrical standards and statutory laws at the same time.
Standards are use as guidelines for Engineers and practitioners to ensure safety of installations or equipments. Designers may or may not comply with them as long as supporting calculations are presented to support the design. In the event of incidents however, it could lead to losing court battles if not complied with.
Standards which are Statutory Laws need to be complied with else the installation will be doomed. It could lead to work stoppage, fines, cancellation of permits or worse imprisonment. In the events that some standards do not have a significant delineation of requirements, statutory requirements prevails.