the player's command includes "[direction]"?

Is there a scalable way to make a topic be understood the way the subject implies?

I could only get it to work by first doing this:

Understand "n/north/s/south/e/east/w/west/nw/northwest/ne/northeast/sw/southwest/se/southeast/u/up/d/down/in/inside/out/outside" as "[direction]"

So, if a new direction is added, it won’t work with that topic. How can I make “[direction]” understood as any text that is understood as a direction?