A new rulebook is reportedly coming into force at Facebook to govern the way workers at the company can discuss religion and politics.
Business Insider said the details of the policy were contained in a leaked memo from the social media platform's chief technology officer Mike Schroepfer.
The new rules apparently forbid employees from trying to change other workers' religious or political beliefs, use harassing speech or bully others.
Mr Schroepfer is reported to have said in the internal memo, sent on Monday, that 'a set of ground rules for open and respectful communication at work, and a central moderation model' had been developed by the company.
The rules largely regulate how staff at the company can use Workplace, Facebook's app for employees to connect, collaborate on projects and keep up to date with company goings-on.
'We're keeping it simple with three main guidelines: Don't insult, bully, or antagonize others,' he is claimed to have said.
'Don't try to change someone's politics or religion. Don't break our rules about harassing speech and expression.'
Facebook spokesman Anthony Harrison insisted in a statement to Business Insider that the rules were not intended to stifle 'openness' or creativity within the company but rather to ensure that internal communication is 'respectful'.
Reported posts will be looked at by a trained moderator, Mr Schroepfer added in the memo, although he did not disclose details of what actions would be taken if a post was determined to have been disrespectful.
'These guidelines apply to all work communications including Workplace, email, chat, tasks, posters, whiteboards, chalkboards, and face-to-face,' Mr Schroepfer wrote.
'Since Workplace is where most of these discussions happen, we are investing engineering resources there.
'We are making it easier to report posts and comments, and those reports will go straight to a trained moderator who'll moderate as needed. We're also developing more tools to help proactively.'
Facebook's workplace culture came under the spotlight last year when one of its former engineers, Brian Amerige, started an internal message group called FB'ers for Political Diversity.
Amerige, a conservative who later left the company, complained of a 'political monoculture that's intolerant of different views'.
According to the Independent, over a hundred employees joined the group.