There was a time when some Japanese rested their weary heads at night on wooden stands rather than pillows. It was popular with geisha girls who didn't want their elaborately coiffured hair disarranged.
The custom virtually disappeared a century ago, but it has taken a long time for the news to reach abroad.
Until a few years ago, a Swedish school textbook insisted that Japanese ''rarely use pillows,'' but often employ wooden stands. The fact that it now concedes that modern Japanese use ordinary pillows is a triumph for a determined Japanese government campaign to correct erroneous or misleading descriptions of the country in foreign texts.
The effort has been under way since 1958, but rarely gained any attention. In recent years interest has centered on the government's efforts to rewrite domestic history textooks, especially in toning down passages about Japanese foreign aggression in the 1930s and 1940s.
The International Society for Educational Information, an affiliate of the Foreign Ministry, has just released a report on its crusading activities for accuracy in the textbooks of 87 other countries so far.
The society has collected more than 20,000 textbooks, maps, and encyclopedias for examination, and a panel of 200 university professors and senior-high-school teachers has been recruited to pore over the material in search of inaccuracies.
To date, the institute says 80 percent have been checked and corrections requested from the publishers or educational authorities involved, mostly with success. Portraits of Japan have gradually shifted for the better, says Fumi Miyamoto, the society's director.
In the 1950s, 8 out of 10 lines of print on average contained perceived inaccuracies. Today, the average is down to 10 percent for European textbooks and even less for the United States.
Reflecting a growing interest in Japan, its main trading partner, Australia, has the best record with less than 2 percent detected inaccuracies, the society reports. But schoolchildren in some Asian countries are still getting a lot of wrong information (an average of 30 percent), perhaps because of out-of-date material channeled from former colonial rulers in the West, it says.
Postwar school textbooks published abroad used to be full of descriptions of 19th-century cliches like geisha girls and rickshaws, according to the society. Later, Japan was pictured in an oversimplified manner as a country poisoning itself by environmental pollution. Since the 1970s the prevailing image has been of an aggressive economic power apt to cause trade friction.
One American textbook, cited by the society as objectionable, contains an illustration of Japan's relations with China. One drawing, labeled ''China 1938, '' shows a Japanese plane dropping bombs. In the next frame, labeled ''China 1978,'' the bomber is dropping a stream of consumer goods like cars and televisions.
Maps cause Japanese authorities a lot of concern, too. There is confusion, says Ms. Miyamoto, over ownership of four northern islands captured by Soviet troops at the end of World War II and still claimed by Japan.
Some maps show them as Russian, some as Japanese, and others as of mixed ownership. The society, the director admits, has been ''less successful'' than in other areas in correcting errors here.
Apart from communicating with textbook and map publishers, the society's dogged efforts for accuracy include overseas seminars and workshops for teachers and students.
The Foreign Ministry reports that in 1983, Japanese diplomats abroad visited 381 schools, including 64 in the United States, ''to keep students posted on today's Japan.''