Where minimum fuel might also help you is enroute,
Interesting. My understanding, from reading the link given by MA, is that minimum fuel means you expect to land with only 30mins fuel. IMHO, en-route, this should only occur when en-route to a diversion airfield. It should not happen en-route to destination. That would mean you had already used your diversion fuel, and therefore should already have diverted. Do we all, all crews & all ATC's in all countries, really understand what "minimum fuel" means?