Lingering uncertainty around Indonesia’s commodity export rules means traders are holding up some shipments just as radical changes come into effect, adding to strains on Southeast Asia’s largest economy.President Prabowo Subianto sowed confusion late last month with the surprise announcement that the country would take control of shipments of key raw materials, including coal and palm oil — a sweeping move for the world’s top exporter of both products. From Monday, exporters are required to report sales documents to the state firm that will have oversight.So far, that has involved checking off a declaration box in the trade ministry’s system confirming their willingness to submit the forms, according to industry sources, who requested anonymity as they were not authorized to speak to the media.