What is the difference between the "AID" and the "RID"?

[wendycwilliams]

In the API documentations it says," Partners: The SeatGeek Platform API has built–in support for partners.

Arguments
aid: optional, default is null
Adding the aid argument will append an aid to all URLs

rid: optional, default is null
Adding the rid argument will append an rid to all URLs

AND the partner documentation for creating manual links says:

To affiliatize any SeatGeek link, append your unique AID (assuming you have signed up for the partner program and obtained you AID) to the end of any link in the following format:

“?aid=xxx” (xxx being your unique AID)

For example, if you want to affiliatize the link to the New York Knicks page on SeatGeek, go to the that page on SeatGeek.com, copy that link, and append your tracking code – https://seatgeek.com/new-york-knicks-tickets?aid=xxx&**_rid=yy_**

If you’d like to link to a particular game or event, go to that page on SeatGeek.com, copy the link, and append your tracking code – https://seatgeek.com/new-york-knicks-tickets?aid=xxx

I understand what the "aid" is but I don't understand what the "rid" is and I don't understand what the "rid=yy" argument in the example above means. What is the "rid" and what does the "yy" mean and do in the example url above?