Until very recently, the children of migrant workers had no right to sit the "gaokao," China'a annual college entrance exam, in their adopted cities, even if they had studied there for most of their academic life.
Since the 1950s, the population has been divided into urban and rural residents. Every adult is issued with a "hukou," the household registration certificate, which binds them to a city, town or village.
This system is like a social passport, guaranteeing families access to health care, education and other support resources. However, and herein lies the problem, the mass movement of people across the country for work has meant that many families are hundreds, if not thousands, of miles away from their registered hometown.
In short, the system does not work in today's China: This is best illustrated by gaokao rules, as currently, most offspring of China's 200 million migrant workers must return to their parents' hometowns to sit the make-or-break test.
On Tuesday, 9.4 million students sat the gaokao, and of that number almost 10,000 had been saved from making the arduous journey back to the countryside.
Guangdong Province in south China was chosen to pilot the gaokao reform program, which allowed the offspring of migrant workers to finally sit the exam alongside their urban peers, providing their parents met certain requirements.
Zhong Mengyao's parents are from southwest China's Sichuan Province and they have worked as sanitary workers in Guangzhou for 20 years. Despite speaking fluent Cantonese and having lived in the city for almost all her life, Zhong can not legally identify as a native of Guangzhou.
"Without a Guangzhou hukou, I always felt I was different from my classmates. I dare not make friends in school in case I am forced to return to Sichuan," said the senior student in Hexie High School in Guangdong's capital of Guangzhou.
On Tuesday, however, she was found taking the national exam along with her classmates in Guangzhou.
Zhong was among the first group of 9,500 migrant students to sit the exam in Guangdong.
"Migrant workers have contributed greatly to Guangdong's development. Many migrant children have gone to school in Guangdong. They must be allowed to take the exam here," said Huang Youwen, deputy head of the provincial examination authority.
Children from migrant families eligible to sit the exam in Guangdong have to meet five requirements -- their parents have stable jobs, a legal residence, a residence permit, social insurance records in Guangdong for three consecutive years, and children's school record in Guangdong for three years.
With the progress in the gaokao reform, it is foreseeable that more migrant workers will bring their children with them instead of leaving them at their rural hometowns.
Guangdong is among only a handful of places that have piloted the gaokao reform. Many education authorities are concerned about "gaokao migration."
"Opening gaokao to migrant students has put Guangdong to the test," said examination official Huang.
He said Guangdong sees around 200,000 migrant children arrive every year. If they are all allowed to study in Guangdong, the province must build 100 more schools.
"The cost of land use and investment for the schools is huge," he said.
Guangdong had 733,000 students to sit gaokao this year, down from 754,000 last year.
Huang said as the number of total examinees reduced this year, there was no need to worry about an increase of migrant examinees.
Education equality is the primary objective of China's gaokao reform, which is a key part of the government's efforts to safeguard social fairness.