Delhi Police Commissioner B.S. Bassi on Sunday cautioned against any form of vigilantism during the odd-even vehicle movement restriction plan here, saying volunteers intended to be deployed by the Delhi government should assist the force as briefed by them."DP (Delhi Police) to enforce odd even. Requesting government: volunteers to assist Delhi Police and to act as told. All Note: rule of law and vigilantism are incompatible," Bassi said in a tweet.The odd-even scheme, mooted by the city government, will be implemented on a trial basis between January 1 and 15.Bassi also elaborated on how volunteers would work. "Once volunteers report to police, they shall be briefed and deployed as per an action plan. No undue harassment of road users is the objective," Bassi added.The odd-even plan for four-wheeled vehicles, unveiled by Delhi Chief Minister Arvind Kejriwal, is aimed at reducing pollution in Delhi.Under the plan, four-wheelers with odd registration numbers would ply on odd dates and those with even numbers would run on even dates. There will be no curbs on Sundays. The scheme will be effective from 8 a.m. to 8 p.m. Some category of vehicles have been exempted from the plan.