Schools in Brazil have started to place computer chips in school uniforms to keep track of pupils and reduce truancy.
Some 20,000 pupils in the north-eastern city of Vitoria da Conquista will have microchips embedded in their school T-shirts.
The parents will get a text message when their children arrive at school, or if they are late for classes.
The authorities say the measure will help teacher-parent relations.
The authorities in Vitoria da Conquista, Bahia state, call the microchipped T-shirts "intelligent uniforms".
They say that by next year all local pupils aged up to 14 would use them.
The city's education director, Coriolano Moraes, says the measure was introduced because parents were not aware that their children were missing school.
"We noticed that many parents would bring their children to school but would not see if they actually entered the building because they always left in a hurry to get to work," he told the Associated Press news agency.
The chips are placed underneath the badge of a school uniform, or on a sleeve.
When a pupil passes through sensors at the school entrance, the chip sends an SMS message to parents.
If they are more than 20 minutes late for class, their families are alerted with a different message: "Your child has still not arrived at school."
The local government has invested about $700,000 (£442, 531) to set up the system.
The authorities in Vitoria da Conquista say the T-shirts can be washed and ironed without damaging the chips.