It says:
Category 5 consists of narcotics which do not belong under category 1 – 4, such as opium.
Permission
In general, unless permission is obtained, the manufacture, import, export, sale, possession and use of narcotics in Thailand is prohibited. . .....................................
Category 5: fine of up to Baht 1,500,000 (one million, five hundred thousand Thai baht) and imprisonment not exceeding 15 years;