The DT400 recall feature can be configured to keep a list of the last 4, 8, or 16 addresses that were previously selected in the throttle.
The number of locomotive addresses stored is determined by changing the values of Option 3 of the DT400; the default setting is 4.
It is not possible to clear out the stored locomotive information held in the stack.
Locomotives in the Recall Stack rotate out as newer locomotives are selected, usually on a FIFO (First In, First Out) basis, but there may be exceptions.
For many users, searching the Recall Stack may complicate matters by providing too much information; those who encounter this may want to configure the Recall Stack capacity downward to make it easier to search for fewer locomotives.
Others may find that simply selecting the desired locomotive by reentering the locomotive to be the best approach.