Legislation making it a criminal offence to mock the national anthem came into effect in Hong Kong on Friday, with police officers already briefed on how to enforce the law.
Sources told RTHK that the force's internal guidelines suggest the legislation should only be used against those who deliberately "insult" the March of the Volunteers. To determine intent, officers could check comments people have made on social media platforms.
Officers have also been advised not to question or arrest students suspected to have broken the law on campus. Sources said the police should first consult with the schools before deciding what action to take.
Breaching the new law can lead to fines of up to HK$50,000 and three years in prison, with the authorities allowed two years from the date of an alleged offence to bring a prosecution.
The law was finally approved by legislators last week after filibustering by the pro-democracy camp had slowed down the bill's progress through the council.
Opposition lawmakers had vehemently opposed the new law, saying it infringes on people's freedom of expression.
They also say legislation is not the right approach to make people respect the anthem.
But the government insists that the law is necessary to show people's respect for the country.
In signing the bill, Chief Executive Carrie Lam said it is of "paramount importance" to educate the city's next generation to understand the history and spirit of the national anthem.
She added that the Education Bureau will update its teaching materials accordingly.
In 2017, Beijing passed its own law outlawing any "insults" to the anthem and inserted this legislation into Annex III of the Basic Law.
The central government's move came after Hong Kong football fans booed the March of the Volunteers at matches on numerous occasions.