Indiana knife law preemption has been introduced this year - https://iga.in.gov/legislative/2015/bills/house/1634. This bill would preempt local regulations on the possession, carrying, transport, sale, transfer, and manufacture of knives. School's would have an exemption to prohibit carrying and possession on school property. Just like firearms preemption, if signed into law it would let you carry your legal at the state level knife without having to keep up with each municipality's own ordinances and restrictions.