Editing Interest rate swap (section)

===Extended description===
{| class="wikitable floatright" | width="250"
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|There are several types of IRS, typically:
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* "Vanilla" fixed for floating
* [[Basis swap]]
* [[Currency swap|Cross currency basis swaps]]
* [[Amortising swap]]
* [[Zero coupon swap]]
* [[Constant maturity swap]]
* [[Overnight indexed swap]]
|}
As [[Over-the-counter (finance)|OTC]] instruments, interest rate swaps (IRSs) can be customised in a number of ways and can be structured to meet the specific needs of the counterparties. 
For example: payment dates could be irregular, the notional of the swap could be [[Amortising swap|amortized]] over time, reset dates (or fixing dates) of the floating rate could be irregular, mandatory break clauses may be inserted into the contract, etc. 
A common form of customisation is often present in '''new issue swaps''' where the fixed leg cashflows are designed to replicate those cashflows received as the coupons on a purchased bond. 
The [[interbank market]], however, only has a few standardised types.

There is no consensus on the scope of naming convention for different types of IRS. 
Even a wide description of IRS contracts only includes those whose legs are denominated in the same currency. 
It is generally accepted that swaps of similar nature whose legs are denominated in different currencies are called [[Currency swap|cross currency basis swaps]]. 
Swaps which are determined on a floating rate index in one currency but whose payments are denominated in another currency are called [[Quanto]]s.

In traditional interest rate derivative terminology an IRS is a '''fixed leg versus floating leg''' derivative contract referencing an '''IBOR''' as the floating leg. 
If the floating leg is redefined to be an [[overnight rate|overnight index]], such as EONIA, SONIA, FFOIS, etc. then this type of swap is generally referred to as an '''overnight indexed swap (OIS)'''. 
Some financial literature may classify OISs as a subset of IRSs and other literature may recognise a distinct separation.

'''Fixed leg versus fixed leg''' swaps are rare, and generally constitute a form of specialised loan agreement.

'''Float leg versus float leg''' swaps are much more common. These are typically termed (single currency) [[basis swap]]s (SBSs). The legs on SBSs will necessarily be different interest indexes, such as 1M LIBOR, 3M LIBOR, 6M LIBOR, SONIA, etc. The pricing of these swaps requires a '''spread''' often quoted in basis points to be added to one of the floating legs in order to satisfy value equivalence.