Boyishgender is a gender for individuals who identify with the term boy, without identifying with a male identity at all. Boyishgender individuals can be any gender or sexuality which is for non-men.
The most important part of this identity is that identifying with it does not make one a man. This gender is completely disconnected from identifying as a man in every way, shape, and form.
The term was coined by jack (@_fluffyfon) on Twitter, on May 13th, 2021.
The meaning on the colors of the flag are as follows: orange represents disconnect from the word man (+ woman, girl, etc), blue represents a connection to the word boy, white represents being non-binary, pink represents a connection to femininity, and yellow represents not identifying as a man or male.
Boyishgender stems from the term boyish, which is used to describe an aspect of something that is traditionally masculine. In terms of the gender, it is used to describe someone who is somewhat a boy, but not a man or male.