The CBOT is preparing to introduce trading in crush spread options.  This advisory provides information about clearing and bookkeeping processing for these new options, including enhancements to the SPAN file generically applicable to any options on futures spreads.

 The crush spread options will use the value 31 as their clearing code.  A typical crush spread option might be a July 2005 call, with a strike price of 0.50, with its underlying being the July 2005 crush spread.  Exercising a long position in this call, means buying 1 July 2005 crush spread at the strike price, which in turn translates into buying 11 of the July 2005 soy meal futures, buying 9 of the July 2005 soy oil futures, and selling 10 of the July 2005 soybean futures.

 So the crush spread options are in some ways analogous to CME's options on 5-year Eurodollar bundles.  You can think of the option as an option on a combination, rather than an option on a future.  The option has a single underlying – the crush spread combination – which in turn breaks out into its underlying legs.