Lawyers in the UK are warning managers not to send emails in capital letters for fear of upsetting more junior staff.
Writing such messages was equivalent to shouting at employees in person and could lead to a complaint or even disciplinary action, according to Britain's biggest employment law practice.
James Davies, head of employment law at Lewis Silkin, said: "It is commonly understood that writing emails in capital letters is equivalent to shouting and would be dealt with by an employer in similar terms. Managers should not put emails in capital letters."
The Chartered Institute of Personnel and Development, which represents human resources managers, issued a similar appeal.
Ben Willmott, head of public policy at the CIPD, said: "You have to be more careful with your use of words in an email because you cannot use facial expressions to convey nuances in meaning or intent. If people constantly use emails in a very shouty or direct manner this could contribute to some sort of issue around bullying."
One law firm said it was aware of as many as 10 cases in which the use of block capitals, as well as other matters, had prompted harassment and bullying claims.
Anthony Sakrouge, head of employment law at Russell-Cooke Solicitors, said: "I have come across numerous cases where using block capitals has been the reason for either a warning or dismissal.
"You could see in those cases they were using capital letters deliberately to show they are shouting. In those cases, maybe he or she [the victim] could show that there was an attempt to intimidate."