Rightly said. I already knew about this analogy, but then, I came across some interesting things, which completely baffled me.
Let me share with you and @pwuser155009269518 (in particular) and other fellows (in general):
As per https://www.pakwheels.com/accessories-spare-parts/cvtf-oil/213224 , as of now, following 03 Toyota Genuine CVTFs are available:
However, when I apply the filter of Toyota Vitz, 2015 model, look what does the website says:
Can you believe that??? 
According to this, neither Toyota CVTF-TC, nor CVTF-FE, is suitable for Toyota Vitz, 2015 model.
Now an interesting thing:
Please have a look at: https://www.pakwheels.com/accessories-spare-parts/toyota-cvt-fe-gear-oil-for-2015-2017-4l-genuine-2649650
It is giving me an option to select ride, and check whether it fits or not. When I enter Toyota Vitz, 2015 model, see, what does it say:
Can you believe that??? 
What to believe and what to not believe?
And...
Now see, what I found written on the CVTF Inlet bolt in engine bay (Please pardon the poor photographs. I took them around 7:25 p.m. tonight, in the torch light, after coming back from office, but they will be self-explanatory):
And surprise:

Toyota Vitz 1.0F (Manufactured: November, 2015) has FE written on CVTF Inlet Bolt! 
I think, there is something wrong with the website. Pakwheels management should seriously look for such issues and rectify them accordingly. If CVTF-TC and CVTF-FE does not fit Toyota Vitz, 2015 model, then which CVTF fits it? 
(I do not know of any other Toyota genuine CVTF, other than TC or FE, and one of these 02 must fit JDM Toyota Vitz, 2015 model.)
I hope, it helps all concerned. Thank you.