Feel strongly about these letters, or any other aspects of the news? Share your views by emailing us your Letter to the Editor at letters@scmp.com or filling in this Google form . Submissions should not exceed 400 words, and must include your full name and address, plus a phone number for verification. I refer to the article , “Covid-19: Hong Kong to step up restriction enforcement with colour-coded app system, but health minister says change not aimed at ‘tracking’ residents” (July 11), about the introduction of real-name registration and a dual-colour system to the “Leave Home Safe” app. Following this, the technology secretary noted that the app already has some real-name functions through users’ vaccine records tied to the app. Besides, a SIM card system requiring registration under the user’s real name, which takes effect from February next year, will also serve the same tracking purpose. I welcome the new policy. I believe it could lay a solid foundation for reopening the border between Hong Kong and the mainland. The outbreak of the coronavirus has caused severe damage to our city’s economy. Considering that mainland China is the most crucial business partner of Hong Kong, reopening the border and restoring the flow of people between the two sides should top the to-do list of the new government. Since the mainland has adopted the “dynamic zero infection” policy, Hong Kong needs to minimise the number of confirmed Covid-19 cases. The new rule not only allows Hong Kong to better monitor the epidemic, but also helps us better adapt to the mainland’s disease prevention measures, as the dual-colour system is similar to the mainland’s health code system . Yet, the government should not neglect the public concern over privacy related to the new health code. Without public support, the effectiveness of the new policy may be adversely affected. Furthermore, the privacy concern over the new rule may even discourage foreigners from coming to Hong Kong, which further impairs Hong Kong’s competitiveness as an international financial hub. Therefore, the government has to spare no effort to address such concerns through public education and promotion. Besides, to avoid public opposition, I suggest the government implement the policy on a step-by-step basis. For example, citizens who plan to travel to the mainland may voluntarily join the upgraded system. The success stories of this stage may be able to attract more to opt-in in the future. Gu Cheak-kai, Sha Tin