Dear Alexis: I looked at the "Sao" link. I think a generic name for it might be "hardtack" a large unleavened bread that used to be naval and military ration chosen because of its superior keeping qualities. When I was a kid it was called "Pilot bread" and often crumbled into a bowl with milk for a quick breakfast of evening meal. Sometimes I ate them with peanut butter on them, but never as a sandwich. I haven't seen them in the stores for many years. They could still be handy to take as rations for long drive or camping trip. I can't think of anything we have comparable to Vegemite.