The Air Force has revised the rules for how it will handle nuclear weapons in the wake of last August’s errant transfer of six nuclear warheads on a B-52. Air Force Instruction 21-204 on Nuclear Weapons Maintenance Procedures, dated Jan. 17, supersedes the previous iteration of document from May 2007. According to the summary of changes in the 153-page document, the instruction is "substantially revised" and USAF says it must be "completely reviewed." USAF expects the revised instruction to address shortcomings in oversight the service identified as having contributed to the “bent spear” incident. Among the more significant changes, the service wants a single individual to perform Munitions Accountable Systems Officer and Weapons Custodian duties, and it prohibits bases from co-mingling nuclear and non-nuclear weapons, including training shapes and empty missiles, in the same storage structure. Additionally, all non-nuclear weapons will have placards indicating their status, such as trainer or empty, "to ensure there is a clear distinction between nuclear and non-nuclear weapons." Last fall during a press briefing on the incident, which service leaders acknowledged broke a long-time precedent, the Air Force announced it had relieved four senior officers of their commands, had taken disciplinary actions against other personnel, and had decertified one bomb wing from its wartime mission.