NANNING - China's decades-old family planning policy has had the effect of shrinking family trees over time, leaving younger people with fewer relatives.

However, the rules that dictate which titles are used to refer to different relatives are still boggling the minds of these same young Chinese.

In traditional Chinese families, where all brothers live under the same roof with their parents even after they are married and have children of their own, the terms "aunt," "uncle" and "cousin" are far from enough to address everyone.

A child has to call his mother's sister "yi ma" (maternal aunt) and the woman's spouse "yi fu." If his mother has several sisters, they are addressed in relation to their age, from "eldest yi ma" and "second yi ma" down to "youngest yi ma."

A mother's brothers are called "jiu jiu" (maternal uncle) and the spouse "jiu ma," also determined by the ages of the relatives in question.

The situation is even more complicated on the father's side of the family. A father's elder brothers are called "bo bo," but the younger ones are "shu shu," which can be confusing even for adults.

There is also a multitude of titles used to describe cousins, as well as elder brothers and sisters. And those are just for direct relations -- the naming conventions become even more complicated when it comes to one's parents' cousins and their spouses.

Some of these words are already being phased out, as the oldest members of the one-child generation born in the 1970s have now become parents themselves. Their children know nothing of aunts, uncles and cousins, since their parents come from single-child families themselves.

A poll of 489 people conducted by the Xinhua News Agency from Saturday to Tuesday found that 72 percent of respondents could not address their relatives properly.

While only less than 20 percent of the respondents said they could manage to address most people properly with their parents' help, nearly 40 percent claimed that even their parents often argue about what to call a distant aunt or uncle.

Wang Fenghui, a college student in Shanghai, said it is "perfectly normal" for him to be unaware of what he should call his mother's cousin.

"I grew up in the city and know very little of our relatives who still live in the countryside," said Wang. "We meet twice a year at most. We meet during Lunar New Year and occasionally during Tomb-Sweeping Festival in the spring, when we worship our ancestors together."

When Mu Jin returned from Sydney to her hometown in Nanning, capital of south China's Guangxi Zhuang autonomous region, her first challenge was figuring out what to call her great-grandmother's younger sister. "I was really frustrated by how poor my Chinese was."

Dr Zeng Fanzhen, a Suzhou University sociologist specializing in Chinese genealogy, said Chinese family trees quite likely represent the most complicated and hierarchical familial system worldwide.

"But the one-child policy and rapid urbanization have downsized families and blurred blood relations," Zeng said.

Larger families are hoping to restore their genealogy to enhance family cohesion among the younger generation, Zeng said.

"This will hopefully help to sustain traditional Chinese family relations, which are an important part of Chinese folk culture," Zeng said.