What is srgb bt.709? I am the author of an add-on for Blender 2.8.

I have one user that is experiencing an error. I understand what is causing it, but I don't understand why.

My add-on is selecting the "Standard" option from this list:



The user, however, does not have that option. Hist list looks like this (note also the different Display Device):



We are both using clean installs of the latest Blender 2.8 beta (11 July 2019 build).

What exactly is "sRGB / BT.709"? Why does he have this option, whereas I do not?
BT.709 is an HDTV color standard, hence different options list. The user mentioned may use such a device. It'd be good if his device had a VGA input either. See color.org site for more info on the subject.