I would prefer it if someone who has gone through the topic would clear this.
Reading this might confuse those who haven’t gone through it.
What is the contingent put in a ratchet bond allow u to do?
Is it basically saying that if the market IR of a floater increases substantially on a reset date then you could excercise your put option?
What is this criteria to be more specific and how does it benefit the investor?
Ratchet bonds start with high coupon rates which can reset to lower rates, usually annually.
If the rate is reset lower, the bondholder can exercise the put and get the bond redeemed at par. It’s called a contingent put because it is contingent on the rate resetting; if the rate doesn’t reset, the bondholder has no right to put the bond.
I used to panic at the word ratchet throughout the curriculum until I visited a friend mechanic and saw a ratchet socket…
In other words, it is doesnot necessarily have an embedded put option?
It is simply putable because it is a floater and has the option to reset to par value on each reset date regardless of the IR at reset date?
Ain’t nobody got time fo that 
I thought ratchet is your rate can only go up?
Then you were mistaken.
At a reset date the coupon rate on a ratchet bond can remain the same or it can decrease. It cannot increase.
It does, necessarily, have an embedded put option. But it’s a contingent put: exercisable only if the coupon rate decreases at a reset date.