corp zeroes are callable like regular coupon notes. they will have a schedule of date and amount. there was a zero coupon float from nationsbank for instance that was callable at a starting point on an annual basis and each year it went up incrementally a bit more. last year or so it was callable at $30 something if memory serves.

treasury strip zeroes though are generally not callable, at least non that i could find. you know thanks for this thread because i forgot something in terms of my proposed shorting STRIPS hypothesis. even though its a zero, the interest still has to be amortized and claimed on annual taxes for the person who is long the bond; so being short makes this a little more complicated or possibly not. maybe it would be just a matter of it being accrued interest similar to what a dealer has to deal with in terms of their own inventory they are holding or trying to sell over a period of time. will have to ask a CPA i know.