At my sailing club, we have a unique ID for each boat that sails (in mutiple config).

So Inter 17 without a kite is "I17"
Inter 17 with the kite is "I17SPI"
Spitfire is spitfire
Someone sometimes sails the Spitfire single handed (with and without kite) and I think he is id's as SpitfireS and SptifireSSpi

We have one F16 that so far is only sailing 2 up (with all 3 sails) so that is as a F16; I assume he will sometimes sail single handed with the Spi and so it will be F16SSpi !

You then have a one-to-one relationship between boat identifier and rating.