Democratic presidential candidates are starting to add their preferred pronouns to their official campaign bios, including their Twitter accounts. So far, former HUD secretary Julian Castro, New York City mayor Bill de Blasio, and Massachusetts Senator Elizabeth Warren have added the trans-friendly marker.

“Stating your pronouns publicly as a cisgender ally sends a strong signal of support to the LGBTQ community but particularly transgender and non-binary people that they are seen, accepted and supported,” HRC spokesperson Lucas Acosta told NBC News after Warren updated her Twitter account to include the pronouns “she/her.”

“Elizabeth is committed to running an inclusive campaign, and wants every person to know that they are welcome in this movement,” Warren campaign spokesperson Alexis Krieg said.

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Warren, how consistently ranks in the top three preferred candidates, is the only one of the top tier candidates to include the information. Vermont Senator Bernie Sanders, former Vice President Joe Biden, and out South Bend, Indiana mayor Pete Buttigieg do not include the information.

Warren recently introduced a bill that would allow same-sex couples to file joint amended tax returns to collect refunds from when they were married but before the federal government recognized those marriages.

In 2004, Massachusetts became the first state to recognize marriage equality. But until the 2013 U.S. v. Windsor Supreme Court decision, the federal government did not recognize same-sex marriages, which meant that married couples had to file federal taxes as if they were single, and usually they paid more.

People can file amended tax returns for up to three years after they originally filed, but the Refund Equality Act would allow same-sex couples who were married before 2013 to file for the entire time that they were married.