As stated above, it will clarify the law and let people know where they stand so we would see ludicrous prosecutions such as those of the gardener who was carriying shears in the back of his car.
The offence of possession an offensive weapon should be scrapped or at the very least redrafted so as to make it absolutely clear when a particular article may or may not be carried.
A few years ago a police officer who battered an elderly man was charged in addition to assault with possessing an offensive weapon. It is clearly absurd to charge a police officer with possessing a truncheon.
A flick knife is a statute barred weapon per se. What is needed is a law of that clarity; this would also prevent malicious or capricious prosecutions.