Since our 31st Commandant, General Charles C. Krulak, first published Marine Corps Reference Publication 6-11D, Sustaining the Transformation, in 1999, the Marine Corps has continued our proud tradition of making Marines, winning battles, and returning quality citizens to society. Like all previous generations, Marines today are equally as committed to our time-honored values of honor, courage, and commitment. Marines of the 21st century are among the finest we have ever forged; it is every Marine's duty to sustain that rich legacy. America trusts its Corps of Marines--we must always strive to preserve that trust. The Marine transformation is forever ingrained in our DNA, from recruit training to Officer Candidates School and throughout the rest of our lives. The transformation to becoming a Marine is often the defining moment in a person's life.