Elon Musk on Tuesday announced that the words “cis” and “cisgender” are now “considered slurs” on Twitter. The billionaire was replying to a user who claimed to have been targeted by trans rights activists after tweeting to say he rejected the word “cis.” The words “cis” and “cisgender” refer to someone whose personal gender identity matches their sex at birth, as opposed to someone who is “trans” or “transgender.” Musk later commented on a Twitter poll asking if “cis” is a slur in which 78 percent of respondents voted “yes.” “People overwhelmingly reject this obvious slur that bigots are trying to impose,” Musk tweeted. It’s not clear if he plans to impose penalties on Twitter accounts using the phrase, with Musk indicating that the platform may only consider the words offensive when used to describe others. He told someone asking if it’s all right to self-identify as cis that they can call themselves “anything you want.”