Nonbinaryflux: refers to a group of people that identify as both transgender and non binary. It is similar to agenderflux except instead of fluctuating from the gender they were born with to non binary, they fluctuate between being an ftm / mtf transgender to non binary. 

The term has only been used recently by a member of a group chat and they proposed the idea for the flag as well. The flag uses both the non binary flag colours and the trans flag colours.

Source: Gender Wiki

-Fy