BEIJING - The austerity drive launched by the Communist Party of China (CPC) in December 2012 has put a brake on official extravagance and spending ahead of the upcoming Chinese festivals.

But caution and supervision is needed to guard against hidden or low-key luxury and bribery.

People are using express delivery or coupons as a means of networking or bribery ahead of the Mid-Autumn Festival, which falls on September 19 this year. Gifts range from tea, crabs to mooncakes.

Some delivery boxes are left with little or no information on the sender, making such bribery invisible or difficult to trace, Xinhua reporters have found.

If such invisible bribery is not exposed or supervised, it will undermine the CPC's efforts to promote clean governance and fight official extravagance.

At the end of 2012, the CPC leadership began to promote an "eight-point" set of guidelines to ban extravagance and formalism from events attended by officials.

After the introduction of the regulation, most officials have disciplined themselves, while some overtly agree but covertly oppose these guidelines.

For example, some officials turned to covert feasts in private clubs or government canteens, some filled mineral water bottles with expensive liquors or have had saunas in farmhouses.

Many have been exposed and have received punishment including demotion or dismissal from public office for underground lavishness, but such punishment seems have failed to deter a few who still dare to offer bribes.

The motivation for people to take such risks is their awareness that they can be rewarded handsomely through bribery. The fundamental cause for bribery is officials' abuse of power.

To tackle corruption, it is imperative to restrict power by "the cage of regulations."

The newly found means of bribery using express delivery or coupons have also showed that the fight against corruption will remain an arduous and long-lasting task.

The CPC's austerity drive has witnessed remarkable progress in fighting corruption so far. It has to be made a long-lasting policy and public supervision is necessary in the promotion of the drive.