There are default command handlers for GET, DROP, WEAR, REMOVE (these all support ALL), INVENTORY,SAVE, LOAD, WAIT and possibly a few others that I can't remember just at the moment. You can also use IT after any verb that expects a noun and it will use the noun from the previous command. For example, EXAMINE AXE, GET IT.
Adventuron may have a list of these somewhere, but I don't think they're properly documented.