Schools are reminding parents not to let their children return to school with banned piercings and hairstyles.
Students have been given a list of 'no no's' reminding them not to go overboard on their appearance this summer.
Banned features include nose rings, false nails, coloured hair, skinny fit trousers and 'tramlines or cat scratches' in their hair.
Some schools have issued photos of the type of footwear to buy and what to avoid including suede shoes, reported Yorkshire Live.
Many have warned their pupils against getting 'extreme' haircuts before they return to the classroom in September.
One school in Yorkshire is warning parents to avoid skinny fit trousers or leggings, as well as various types of footwear, from unbuckle to suede.
Staff at Beckfoot Oakbank are also asking pupils to wear formal black leather shoes and the branded uniform, including a polo shirt, jumper and PE kit.
Details of the uniform requirements were conveyed to parents in a letter sent home earlier this month.
The school is keen for pupils' physical appearance to be as plain as possible.
This includes discreet make-up, no false nails, one stud earring in each ear, natural coloured hair and no facial piercings.
A school spokesperson said: "We are now planning for September and want to ensure that our expectations around school uniforms are as clear as our expectations of the students' behaviour.
"No tramlines, cat scratches or other patterns shaved into the hair or eyebrows.
"Only school-issued badges are to be worn on your school uniform."
Staff at Colne Valley High in Huddersfield have also issued a strict warning before pupils return to school in September.
Black shoes and skirts of an 'appropriate length' must be worn at the school which bans trainers.
A spokesperson said the school is proud of its uniform and expects its students "to wear it every day with pride".
Appleton Academy in Bradford has reminded students not to return to class with false eyelashes and issued a similar warning on footwear.
Students must wear black "polishable" shoes and "under no circumstances will the wearing of trainers with school uniform be acceptable."
Trousers must be dark grey and tailored with no leggings allowed.
Piercings should be limited to one small stud in each ear while hair must be a natural colour.
False eyelashes and false nails are not allowed and nails should not be painted except for natural varnish.
Hanson School, also in Bradford, has told students not to come back with 'extreme haircuts.'
Staff said that black tailored trousers must be worn with no jeans or leggings.
School footwear must be completely black whether these are trainers or shoes.
Outdoor coats and hoodies must be removed when entering school and facial piercings are banned.
A small pair of studs in ear lobes are allowed.
A spokesperson said: "Extreme haircuts and vivid colours are not permitted."
Students who attend the nearby Dixons Academy have been told not to wear 'fashion statement belts' when they return.
Instead belts must be plain black and not worn over jumpers or shirts.
Similar rules apply on trousers, with flared and knee-length bottoms also banned.
Shoes "must be sensible and entirely black" and facial jewellery or visible body piercing is inadmissible.
Hair should be "appropriate to a place of work" with no unusual styles or colours, shavings or patterns.
The school said: "Students will be asked to rectify any hairstyle, or replace any clothing at their expense that is perceived to be unsuitable for school. "
