Experience indicates that riot control formations are neither desirable nor necessary for normal demonstration control. A minimum display of force is generally favored, backed up by a strike force kept out of sight until needed. Mobile formations are being used by police to deal with spontaneous demonstrations which have the potential for developing into riots. In tense, potential riot situations, the goal is to quickly and professionally defuse the situation and then withdraw to let the crowd settle down. In most cases, police should not completely seal off the crowd; when the objective is arrest rather than containment, a cordon of vehicles can seal off the area in which arrests are to be made. Teamwork and sufficient manpower are neccessary for mass arrests. Procedures should include a field arrest form to link the officer to the person arrested, and an officer should never arrest more people than he can identify in court. A mass arrest team of 3 officers can handle up to 30 arrests efficiently while maintaining an accounting of those arrested. The negotiated arrest also is part of the control process, as a demonstrator determined to be arrested will escalate the level of provocation to dangerous levels. The negotiated arrest flows from information sharing between demonstration leadership and police, permitting the ensuing action to take on the efficiency of a cooperative plan. In the case of symbolic acts, such as blocking doors, officers must have enforcement priorities, be disciplined, and take care not to be drawn into useless confrontations. Developing an accurate crowd estimate is an important part of control. Use of stationary observers permits estimates of moving crowds, such as those in a parade. Estimating a stationary crowd also is a matter of counting and multiplication. For large crowds the estimator works with a fixed grid in which the density of the crowd is estimated within the known space. Maintenance of accurate records and logbooks space. Maintenance of accurate records and logbooks is important for reviewing the control effort, planning future efforts, and aiding in recall for testimony.