We try, though not always successfully.

I've found this, which suggests (bearing in mind the poor translation and my non-existent Italian) that at one time it was supplied with the HTR-5740 home theatre receiver. As the link goes on to say though, the only manual apparently available, is the North American version and that, according to this (select "Concert Receiver's" and scroll down the list), was supplied with the RAV250.

Taking a lead from the US Yamaha site though, I checked the manuals for both the HTR-5630 (select Audio & Video Product / AV Receivers and scroll down the list) and the HTR-5730. Both of these models purportedly use the RAV300, which does, if this image is to be believed . . .



. . . at least looks like the RAV302. Unfortunately though, with Yamaha looks don't necessarily mean they use the same codes, but it's the best I can come up with.