This Specification is based on successful past use, advances in the state of knowledge, and changes in design practices. The 2016 version of the American Institute of Steel Construction's Specification for Steel Construction provides an integrated treatment for Allowable Stress Design (ASD) and for Load and Resistance Design Factors (LRDF), and replaces previous specifications. As indicated in Chapter B of this specification, the design can be carried out in accordance with ASD or LRFD provisions.