Help figuring out whats going on under my kitchen sink

[mcdb84]

Hi everyone, trying to figure out why the function of the third supply line with the white stopper valve (I think that is what it is called). The first picture shows 4 valves. The Top left is my Hot Water supply, the Top Right is my Cold Water supply, The bottom left is for my dishwaher. I have no idea what the bottom right line is for.

I took a picture of a different angle of the two right lines. The top and bottom right supply lines are connected together with one line coming out of the bottom valve to my Reverse Osmosis system. I'm going nuts trying to figure the function of the bottom right line. When I close it, it doesn't shut anything off. It seems like the only function is to allow my reverse osmosis line to be tapped into my cold water supply line without having to use a feed water saddle valve.

Any help would be much appreciated.

 

[hj]

Your picture does NOT show EVERYTHING. It could be a feed going to your water supply to the refrigerator.

 

[Sponsor]

 

[mcdb84]

Sir, you are correct. Thank you!