What is a suri?

[Upayavira]

In the CLI code, there is a variable called suri. I've never been able 
to work out what its name means, and thus what its purpose is. Can 
anyone explain?

Also, there are points in the code where a URI is deparameterized and 
then reparameterized. What is the point in this?

Regards, Upayavira