United States. 2012-03-10. LETS Vlaanderen LETSystem. Vlaanderen. Belgium. 2012-03-09. PR-LETS Local Exchange Trading System (LETS). Powell River to Community Exchange Systems (CES) and Local Energy Trading Systems can't barter but they can trade in CES/LETS using the local alternative currency. Home page of ABC Lets Local Exchange Trading Scheme. Trade with members using BEES rather than real money.