Two points are worth noting. First, the three layers apply together — satisfying the steel design standard does not by itself satisfy the building code or the load standard, and each has to be demonstrated separately. Second, codes are revised periodically and local authorities amend them, so always confirm the edition, the national annex and any local amendment in force at the time of design. This table identifies the code families in each region, not the specific clause, load factor or edition applicable to a given project.