[Begin image ID: Four separate flags with vertical stripes, two versions for each term. The first is the intraabin flag. From left to right the stripes are yellow, a light orange thin stripe, a dark orange thin stripe, white, a dark orange stripe,  a light orange stripe, and a yellow stripe. The other flag is the same, only with the color of the thin stripes swapped. The intraneu flag has green stripes.

Beside each flag are additional versions with the  matching gender symbols drawn on top, in black. The intramasc symbol is  the male or mars symbol, with the arrow pointing straight down. The  circle has has short, straight lines poking out either side of the  circle. The intrafem symbol is the female or venus symbol, with the  cross pointing straight up. The circle also has small lines on either  side of its circle.  The intramascfem symbol is a combination of the previous two, with the cross on top and arrow on the bottom. End image ID.]

Coining post for intraabin and intraneu

🧡 Intraabin: A gender identity which encompasses infinite, largely varied feelings of abenine and abinary genders. A person might feel different types or amounts of abinarity and abinary-ness, and may use varied gendered terms to describe these feelings. Examples include: abinary, demiabinary, genderknown, libramaverique, etc. Intraabins can experience non-ABIN genders, but their abinarity and abinary-ness is the most important, expansive, constant part of them.

💚 Intraneu:  A gender identity which encompasses infinite, largely varied feelings of neutral and neutrois genders. A person might feel different types or amounts of neutrality and neutrois-ness, and may use varied gendered terms to describe these feelings. Examples include: neutrois, demineutrois, juxtaneu, libraneutral, etc. Intraneus can experience non-NIN genders, but their neutrality and neutrois-ness is the most  important, expansive, constant part of them.

Flags:

💛 Yellow - Abinary gender, the nonbinary nature of the identities.

🧡 Orange - ABIN gender. Two different oranges are used to represent different forms of gender, or gendered feelings.

💚 Green - NIN gender. Two different greens are used to represent different forms of gender, or gendered feelings.

Incredibly late answer, sorry! The intraabin symbol is based off the abinary symbol proposed by waxingoccult, who is deactivated. I don't remember exactly which archive blog I found it from at the time, but here's a link to one of them.

I do still have the intraabin and the general abinary symbols I made, though!

link for the flag:https://www.tumblr.com/i-love-my-trans-body/676927928803770368/begin-image-id-four-separate-flags-with-vertical

I've never seen that symbol before so maybe the symbol was made specifically for that flag?

I think the image description might be wrong because it talks about the intrafem and intramasc symbols instead of the symbols being used in the post. I was hoping the description might tell me more.

After looking around, I couldn't find any abinary symbol at all. I'm going to assume a new one was made just for that flag.