The RFXtrx433 receives the protocols listed in chapter 2.2 of the RFXtrx433 User Guide.
These protocols are hard coded in the RFXtrx433 and have to be proven to operate OK. The most important and commodity products are supported.
The protocols supported by Domotics are also documented and the links are on this page:
http://sourceforge.net/p/domoticz/wiki/Home/
There are thousands of different sensors and remotes operating at 433.92MHz but only the listed are supported.
In general, if a product is not on the supported list it is not supported!