The Education Ministry has amended regulations governing students' hairstyles and dress code after some children decried the previous code as an infringement of their human rights.
The decision came after a number of protests were held by student groups in Bangkok and the provinces.
Somkiat Tangkitvanich, president of the Thailand Development Research Institute who chaired a committee considering the students' demands, said three amendments had been agreed.
First, he said, the prologue to the guidelines would be corrected to embrace participation and reflect present trends, human rights, dignity and sexual diversity.
Second, the rules governing hairstyles would become gender-neutral, with long or short hairstyles permitted for all pupils -- however, hair dying, beards and moustaches remain prohibited.
Finally, schools will be allowed to draw up and implement their own guidelines in consultation with students, teachers and parents.
Mr Somkiat also said that punishments for any violation of the rules must not breach students' human rights, especially if they could be regarded as acts of violence.
In terms of allowing students to dress according to their preferred gender identities, the committee felt the current regulations afforded schools sufficient flexibility to allow this but a greater emphasis would now be placed on participation.
While the power previously lay with schools to implement their own codes, it could also be done by executives but under the new code, all changes must be approved by school committees, students, teachers and parents.