Why focus on the 2011 edition? In many U.S. jurisdictions, building codes update on a 3-to-6-year cycle. However, ACI 318-11 represented the last major code cycle before the significant reorganization introduced in ACI 318-14 (which renumbered almost everything). Many existing building stock, infrastructure projects, and university curricula are still firmly rooted in the -11 framework. Furthermore, the NCEES PE Structural exam historically referenced ACI 318-11 for a long period, making the PCA Notes for this edition a critical study resource.
Enhanced requirements for reinforcement continuity to prevent progressive collapse. pca notes on aci 318-11 building code