Many advocates commended the decision to include pronoun choices in the White House contact form.

The new president has also addressed workplace discrimination and transgender rights in the military.

This focus on LGBT rights is being seen as a marked shift from the Trump administration.

What has the White House done on pronouns?

Only a matter of days into his presidency, Mr Biden has set the tone for his administration's culture when it comes to gender inclusivity.

On Thursday, 24 hours after his inauguration, the White House released its new contact form, which includes the option for users to select their pronouns of choice, first reported by the Gay & Lesbian Alliance Against Defamation (GLAAD).

The revamped website allows users to select from a dropdown list of pronouns which include "he/him", "she/her", the gender-neutral "they/them" or "prefer not to share".

The contact form has also been updated to include the gender-neutral prefix Mx, alongside the more traditional Mr, Mrs and Ms.

So, what are gender-neutral pronouns?

Gender-neutral pronouns are defined by the LGBTQ+ Resource Center as providing an identity for a singular person who does not identify as he/him or she/her.

In English, the word "they" is used as a gender-neutral singular pronoun - even though some critics argue that "they" should really only be used to refer to plural nouns.

In recent years, there has been a growing urge for people to share their preferred pronouns upon meeting and through correspondence - particularly in email signatures.

A number of companies have also made inroads on gender inclusivity in the workplace.

In 2019, The Chicago Tribune reported that IBM had published a white paper on gender transition. Similarly, Quartz reported that financial services firm TIAA issued new guidelines for employees to share their preferred pronouns with clients.

The LGBTQ+ Resource Center at the University of Milwaukee, Wisconsin, adds that asking someone their preferred pronoun, as opposed to assuming from how they present, is a sign of respect for their gender identity.

Why do pronouns matter?

While the Biden administration's contact form may seem like a small step, many see it as sending a powerful message.

"It signals out of the gate, that this administration values diversity and inclusion," Sarah Kate Ellis, CEO of Glaad, told BBC News.

"We know that when people are recognised for who they are and how they present they are less likely to harm themselves and feel more included in society."

A study by LGBT suicide prevention organisation The Trevor Project found that young people whose pronouns were respected attempted suicide at half the rate of those whose pronouns were not.

For Aithan Peterson, 35, being able to use their preferred pronouns has been liberating. "It was something that I immediately identified with," they said.

Peterson also explained that when someone begins a conversation by asking for their preferred pronouns, it puts them at ease.

"Otherwise I'm having to work it into the first minutes of a conversation with someone you don't know well," they said.

"It takes a little bit of the weight off self-advocacy."

The new White House contact form contrasts starkly from Mr Trump's first days in office.

In January 2017, the previous administration immediately removed a web page dedicated to LGBT rights that had been designed by the Obama White House.

Are gender-neutral pronouns recognised by the law?

Although non-binary is not a recognised legal identity at the federal level in the US, a number of states, like Oregon, California and Colorado, do offer non-binary options on identification documents such as drivers licenses.

In 2016, former soldier James Shupe became the first person in the United States to gain legal recognition of his non-binary identity in Oregon.

However, in 2019, Mr Shupe announced that he no longer identifies as non-binary and has returned to his "male birth sex".

What else has Biden done for LGBT rights?

One of the flurry of executive orders that the president signed on his first day upholds the Supreme Court's ruling from June 2020, which prohibits workplace discrimination on the basis of sexual orientation and gender identity.

In a statement, Alphonso David, president of LGBT advocacy group Human Rights Campaign said this executive order was "the most wide-ranging executive order concerning sexual orientation and gender identity ever issued by a United States president."

On Monday, President Biden also signed an executive order that reversed the Trump-era ban on transgender people serving in the military.

Mr Biden has also begun the process of diversifying his administration from the top down. Pete Buttigieg's nomination as transportation secretary means that he is likely to soon become the first openly gay cabinet secretary in US history.

Similarly, the nomination of Dr Rachel Levine as assistant secretary of Health and Human Services would make her the highest ranking transgender official in US history, if confirmed by the Senate.

According to Ms Ellis, the Biden administration has already shown its commitment to all Americans in a short space of time. "In their first 48 hours they are the most LGBTQ progressive administration we have ever seen," she said.

'A new tone on the world stage'

The Biden administration has brought LGBT people into a conversation that they have been intentionally excluded from for the past four years.

This is only day six, but there have already been some historic moments.

For LGBT Americans, and their allies, it will be reassuring that President Biden is delivering on his election promises so quickly.

Leaders of international LGBT organisations have told me they are "breathing a sigh of relief", and they expect these changes will be felt beyond the US.

Those at Stonewall, Europe's leading LGBT charity, said they hope that this era will "set a new tone on the world stage that LGBT rights are not something to be debated, but rather protected and progressed."

However, with the Democrats' wafer-thin Senate majority, some LGBT people are cautious about celebrating the future "too soon".

Many tell me they are "worried" that the Biden administration will not be able to secure enough votes to push through all of their intended LGBT policy changes.

But if they can, the future looks even brighter for LGBT Americans.

Has there been any criticism?

In 2019, a Gallup poll found that 71% of Americans support transgender people serving in the military.

And the president's decision to repeal Donald Trump's ban was met with praise.

"Any individual qualified and capable of joining the military should have the right to serve, period," said Jennifer Dane, Executive Director of Modern Military Association of America - the country's largest non-profit dedicated to LGBT military and veterans.

However, conservative critics say it comes with a price tag.

"President Biden is diverting precious dollars from mission-critical training to something as controversial as gender reassignment surgery," said Tony Perkins, President of Family Research Council.

A Pentagon study suggests healthcare costs would be below $10m a year.