Best to use a 38kHz receiver rather than 36kHz if you are planning on decoding various protocols.

Philips (RC5 RC6 RCMM) tend to be 36kHz and uses Manchester Encoding

NEC tend to be 38kHz and uses space encoding

Sony tend to be 40kHz and uses pulse encoding

Sensitivity of the receiver drops off outside its designated centre frequency so 38k works best as a generic receiver. eg TSOP1238, TSOP1838, TSOP4838 etc