lead processing - disqualifying

Hello,

Since I can't get anyone at NetSuite to answer my support case, I thought I'd try here.  I am looking for guidance on lead processing. Say I import a list of leads and they are in the default status of "unqualified". As I call down the list, someone tells me that they're not interested. What do people typically do to mark that customer as disqualified?

I wouldn't assume that people typically leave it as "unqualified" since you couldn't really tell the difference between someone unqualified ("new") or someone disqualified. Do people create a status like "disqualified"? But then my understanding is those leads would still show up in the list? Do people mark those leads as inactive? Do they delete them (but then you would lose all history, right?)?