The official guidance issued by the UK Boarding Schools Association calls on teachers to address transgender pupils as "zie" to avoid offence, The Sunday Telegraph reported.
Staff have been told they need to learn a "new language" for a growing number of pupils who demand not to be addressed as 'he' or 'she'.
Zie is considered a gender-neutral pronoun which has been gaining ground in its usage across Europe and British teachers are being advised to address children by their "pronoun of choice", including they or 'zie'.
"Schools need to make sure that all students are treated equally and fairly according to the Equality Act," she told the newspaper.
"We need to educate adults to speak a common language because we grew up in a generation with no prior experience about the (lesbian, gay, bisexual and trans communities)," she said.
New guidance also reminds schools in England, Wales and Scotland of their obligations under the Equality Act 2010 under which gender identity and "reassignment" is one of so-called protected characteristics.