China has introduced a tougher regulation to take a firmer grip on the country's internet advertising industry following the death of a college student, who sought treatment for his disease on online search giant Baidu Inc. [Photo/VCG]

3. Restrictions on online ads

The regulation defines paid search ads promoting products or services as internet advertisement.

It said internet advertisements need to be marked as "ads".

The ads involved with medical service, medication, food for special medical purposes, medical instruments, farm chemicals, veterinary medicine, health care products cannot be issued without inspection.

Pop-up ads are required to clearly display the "close" sign and should close as soon as the user clicks on the sign.