What is a "reference" system?

My system IS my reference, the one that is most familiar to me.
I hear and know it's abilities and it's weaknesses.
I'm busy tweaking my diy's, so it's one ongoing project is to improve what 'it' is 'hearing' and do some r/t analysis on some screens.

...but the fun part is getting to play anything I want from a planet of choices.... ;)

....shooting for 'silky'...

Frankly, it's whatever you say it is. For some people, it could be the $1 million dollar system at AXPONA that featured the new $395k Wilson Audio XVX speakers. For someone else, it could be an NAD 3020 driving a pair of Dayton Audio Classic C65 speakers that cost $75 a pair. 

To me, the concept of a "reference" system is just another aspect of "audiophilia nervosa."

Interesting comments IMO. My thoughts - Your system is, of course your reference, since it's what you listen to, you have no choice, but that does not make it, "Reference system" caliber. To me a reference system is one with a level of musical realism that is much closer to the recorded event than a facsimile. This requires a level of clarity, tonal accuracy, dynamic capability and spacial accuracy that the vast majority of systems (including the room and appropriate acoustic treatment) don't achieve. And due to the tonal accuracy and dynamics requirements, it usually requires quite large speakers of very high - quality output capability along with an equally high - quality system.