Isogender

Isogender is a gender modality that refers to when one is not cisgender, but also does not identify as transgender either. Examples of individuals who may identify as isogender include:
 * A bigender, or otherwise multigender, individual who doesn't really feel transgender as a significant portion of their gender strongly resembles/is the same as their AGAB and isn't dysphoric towards their gender.
 * A non-binary individual who doesn't really feel transgender as their gender is strongly similar to their assigned gender as birth. For example, a feminine-aligned non-binary individual who is AFAB can be considered isogender.
 * Someone who stops feeling gender incongruence sometimes or someone whose gender incongruence fluctuates in intensity.
 * An agender or otherwise genderless individual who does not feel like transgender describes them due to the fact that their gender does not exist.

Isogender vs Absgender
Isogender and absgender are strongly similar terms in that they both describe not being cisgender nor transgender, but they cannot be described as synonymous. Isogender means being neither cis nor trans, for whatever reason. Absgender means being removed from, in between or beyond from cis/trans dichotomy.

Although these terms are not the same, some absgender individuals may also identify as isogender, and some isogender individuals may also identify as absgender.

Isogender vs Centrgender
Isogender and centrgender are strongly similar terms in that they both describe not being cisgender nor transgender, but they cannot be described as synonymous. Isogender is for those who aren't cisgender or are not fully cisgender, but transgender doesn't seem to fit either. Centrgender is for anyone who cannot fit into the categories of transgender or cisgender. Centrgender can be either used as its own, or as an umbrella term. As an umbrella term, centrgender would include both isogender and absgender.

Although the terms are almost the same, they are still different terms. However, some isogender people also identify as centrgender, and some centrgender people also identify as isogender.

History
Isogender was coined by an anonymous ask to Tumblr user Bigendering on June 9, 2017. The term "iso" comes from the word isomer, as cis and trans are isomer types.

Flags
The isogender flag was submitted on Tumblr blog beyond-mogai-pride-flags on May 20, 2018.

An alternate flag was created and submitted to Tumblr blog ask-pride-color-schemes on October 22, 2019 and to beyond-mogai-pride-flags on August 31, 2019, with the color meanings as follows: Blue, purple, and pink represent masc, fem, and those who may be a mix of both. The greyscale gradient represents attachment or intensity of gender, from white (entirely agender) to dark grey (strong attachment).

Two tweaked isogender flags were created by Tumblr user Noname-Nonamorous on August 24, 2021 from Beyond-MOGAI-Pride-Flags' design. The flag took the original isogender flag and adjusted the colors, made to look less bright and easier on the eyes. One of the flag features a disk symbol, coming from how iso, the shortening of isogender, is also a disk file type.