In the URL GET parameter ?What is the meaning of parentheses in aa={ab-cd-ef}?

Literally, it looks like you're passing it to {ab-cd-ef} with the value of zz.

I think it might have been used to receive multiple values (ab, cd, ef) as a parameter, or to distinguish the values. For braces, you can remove them from the server end.

The hash code site uses '-' instead of space. You can tell by looking at the current url. If I remember correctly, Google would be using '+' instead of spacing.