Guidance on the use of mobile phones with camera and video capabilities by school pupils has been issued to head teachers by Glasgow City Council.
Glasgow City Council said mobile phones are regarded as essential
A letter issued to every school offers advice on formulating a policy.
The council said it would not be appropriate to ban mobile phones but said they should be turned off and put away during the school day.
It comes after an incident in which a 15-year-old boy was filmed allegedly assaulting a Borders rector.
In the letter, George Gardner, depute director of education services, said all schools should formulate a policy on mobile phone use.
In his guidance, he said: "Many young people and parents regard these as essential means of communication.
"However, while mobile phones can continue to be brought into schools, there must be strict limitations on their use.
"All phones should be turned off during the school day and put away during lessons."
He added: "It would be a misuse of a mobile phone to record staff or other pupils without permission."
Mr Gardner said the policy should be explicit about the confiscation of mobile phones if it is breached.
A head teacher or senior teacher, the letter advised, should arrange the return of the phone.
Parents will be informed of the policy once it is agreed.
Last year, the Educational Institute of Scotland teachers' union passed a motion calling for more responsible use of mobile phones in the classroom.
Lothian and Borders Police have reported a 15-year-old to the Children's Panel in connection with the alleged assault on the head teacher.