This Arabic letters called "Halal" which are usually use on food product packages. It's a symbol of food are allowed for Muslims and means cleanness follow from food production standard.
Halal food standard in Thailand are reliable. The Halal standard institute of Thailand is an organization which have responsibility to examine food products follow from Islamic laws before allow that product use Halal symbol and control Halal foods standard production after product admited to use Halal symbol.
Islamic laws
According to these guidelines gathered from the Qu'ran, Muslim followers cannot consume the following: * pork or pork by products
* animals that were dead prior to slaughtering
* animals not slaughtered properly or not slaughtered in the name of Allah
* blood and blood by products
* alcohol
* carnivorous animals
* birds of prey
* land animals without external ears