Schools have been told to help make uniforms cheaper and allow gender neutral items in a radical shake-up.
The Welsh Government has issued new guidelines - which come into force on September 1 - aimed at reducing the cost of a secondary school uniform, which is now £340 per child per year.
Under the new rules, clothing items would not be assigned to a specific gender.
For example, trousers or shorts would not be described as a "boys' item".
Schools will also be expected to consider whether school logos are necessary and if they should apply to just one item of uniform or be provided free of charge, Wales Online reports.
They will also have to consider whether there is a need for different uniforms for summer and winter.
A consultation was launched last autumn following the summer heatwave in which some parents claimed uniform policies were too strict. During the consultation, respondents backed the introduction of gender-neutral uniforms.
At Cyfarthfa High School in Merthyr some boys went to classes in skirts to protest against a ban on shorts.
One respondent to the consultation wrote: "This should include the choice for all children as to whether they wear trousers or skirts, regardless of their gender assignment or sexuality."
Another said: "The question of gender of a school uniform should be addressed by allowing those pupils with gender fluidity to wear either gender of uniform as required, without discrimination.
"The practicality of having a uniform policy that prescribes only gender neutral garments would be difficult to fulfil. However having a policy that allows children to wear any garments that form a part of the uniform policy should be allowed and encouraged."
The Welsh Government provides £125 for students eligible for free school meals to buy uniforms and other equipment through the pupil development grant.
Eligible Year 7 pupils are also entitled to a grant of £200 to help with the costs when beginning secondary school.
Minister for Education Kirsty Williams said: "Families will know how expensive new uniforms can be.
"This guidance puts a statutory responsibility on schools to consider the affordability, access and availability when setting their school uniform and appearance policy.
"This guidance will help reduce the burden on families, so our children can focus on fulfilling their potential and enjoying a healthy academic and social life.
"We should not be enforcing outdated ideas of what clothes are suitable for their gender, especially if it makes them wear something they feel uncomfortable wearing.
"This new guidance makes clear that school uniform policies should not dictate items of clothing based on gender."
