With tourism booming, pictograms have become an important tool for restaurants eager to describe the ingredients they use to customers whose allergies or religious beliefs require them to avoid certain foods.

While visitors from overseas spent ¥4.4 trillion ($39.7 billion) in Japan last year, the tourism and restaurant industries believe there is potential for further growth if visitors can be made to feel more comfortable when dining.

In early April at a buffet-style restaurant in a hotel in bustling Osaka, foreign customers could be seen looking at pictograms indicating the ingredients used in popular meals such as roast beef and steamed fish in wine sauce. The 14 icons — including cow, pig, peanut and wheat symbols — were developed by Foodpict Inc. based on a survey of 1,500 foreign and Japanese people. They are being used at around 1,400 eateries across the nation.

"They are popular among foreigners who don't understand the Japanese language as well as Japanese people who have food allergies," Foodpict President Nobutaka Kikuchi said.

The Kobe-based company also runs a website where users can use the pictograms to search for restaurants offering suitable dishes.

Tokyo-based Food Diversity Inc. also operates a website for Muslim visitors and residents that allows people to use the pictograms to search menus from around 850 restaurants that comply with Muslim dietary rules, as well as restaurants with Muslim owners and cooks.