Employers are required to use transgender people's preferred pronouns under the New York City Human Rights Law, the city said Monday.

The New York City Commission on Human Rights issued new guidelines to protect transgender and gender non-conforming New Yorkers in employment, public accommodations and housing.

Under the city's Human Rights Law, landlords, employers and businesses must refer to transgender people using their preferred pronouns. Transgender people must also have access to bathrooms consistent with their gender identity.

The New York City Commission on Human Rights also warns that dress codes can be discriminatory.

"Under the NYCHRL, employers and covered entities may not require dress codes or uniforms, or apply grooming or appearance standards, that impose different requirements for individuals based on sex or gender," the guidelines say.

Mayor Bill de Blasio said in a statement that the guidelines strengthen discrimination laws "by ensuring that every transgender and gender non-conforming person in New York receives the dignity and respect they deserve."