Mandatory training is required by the State government, P.O.S.T., or the standard operating procedures of the Irvine Police Department. Essential training is that which would increase the knowledge and skill level of the employee in the current job assignment, but is not mandatory training. Desirable training is that which would enhance the skills and knowledge already learned in the employee's current job assignment, but is not mandatory or essential training. Training topics and numbers of hours are listed for police executives, managers, supervisors, police officers, investigators, traffic officers, personnel with collateral assignments, and nonsworn police personnel.