What is the forward rated current of a diode

The rated current of a diode is its main nominal value, for example, for a 5A/100V diode, 5A is the rated current. The usual definition of rated current is the rated average current that the diode can pass through.
But some tests are conducted with square waves, which means that a square wave current with an average value of 5A can be used. Some tests require direct current, which means they can pass a direct current of 5A. In theory, for silicon diodes, diodes tested with square waves can pass through larger DC currents because square waves with the same average current will cause greater losses to the diode compared to DC currents. So can a 5A diode necessarily pass a current of 5A? Not necessarily, it's related to temperature. When your heat dissipation conditions are not good enough, the current that the diode can pass through will be limited by the junction temperature.