I have also stumbled upon that command one time and never went back to figure out what it is for because it is unknown right now to us. But it probably has something to do with adding a new projectile which would be cool. Only one problem with that idea is that it calls for reals and no strings for images or extra coding. It would be cool to do that though and add new explosion types. It would cut down on our part with scripting new stuff like poison arrows and FlameThrowers explosion fire type.
Do I get a cookie now?
