Nocissexual

Nocissexual is the attraction to all genders, except, either: A) One's attraction fades once it is known someone is cisgender. B) One does not feel attraction to people until it is known that the person in question is not cisgender, or C) One chooses not to date cisgender people/chooses not to date people unless they know the person in question is not cis.

The term is used by transgender, non-binary, or otherwise non-cis people who are unwilling to date cis people. The unwillingness to date cis men/women is not because there’s any inherent difference between cis and trans men/women, rather it stems from issues of safety, trauma, oppression, or other personal reasons. One may not want to be vulnerable to misconceptions, misgendering, or oppression from their partner. One may also prefer a trans partner because one would relate to them more.

It is similar to TLT (trans loving trans), also known as T4T (trans for trans).

History
A similar term was coined in 2014, called undisexual, but it didn't get popular. The first recorded/registered mention of nocissexual is found via Tumblr on anon sent to the user nonbinary-support in April 15th, 2016. It was renamed alternatively as noctic on February 8, 2018 by tumblr user identity-workshop.

Flag
The first nocissexual flag created on the Tumblr blog beyond-mogai-pride-flags on October 29, 2017. It was based off the designs of the nocismasexual and nociswomasexual flags.

An alternate flag, based on the design of the original, was created on July 30, 2020 by Tumblr user Rainbowcoric. The black outer stripes, as well as the line striking through, represent the lack of attraction to cis people or the decision to not date cis people. The white stripe represents the trans people using the label. It is also based off an alternate design for the nocismasexual and nociswomasexual flags.

Preference vs modifier
This term is often called a preference, however many nocissexual people feel no attraction to cisgender individuals, due to personal reasons. Because of this, it cannot exactly be defined as a preference, however it is not exactly a sexuality either. Instead, its best described as a modifier to add to ones sexual orientation. Being nocissexual as well as being cissexual are both due to mental or emotional health, or struggles with connection, and classifying those as a preference can be harmful and misinforming.