Even schoolchildren are subject to the unwritten policies, which have led to the emigration of ethnic Russians, Kazakhs, and Uzbeks.
The latest manifestation is the arrival in neighboring Uzbekistan of young women who married Turkmen citizens but were rejected registration and tossed out of the country, along with their children.
Ziyoda Ruzimova lived in Turkmenistan for more than a decade. All four of her children were born there, and her husband is still there.
But that was not enough to prevent her from being dumped on the Turkmen-Uzbek border earlier this year -- seemingly because she is an ethnic Uzbek. Other Uzbek women have suffered similar fates, according to people who inhabit the area.
Turkmen authorities rounded up Ruzimova and her children in February.
"They brought us to the Shovat border post and handed us over to the Uzbek border guards," Ruzimova recounts. "We had no money. The Uzbek militia helped us; they said, 'Don't cry, you are home. Be happy.' I asked how I could feed my four children, and the militia said, 'Don't cry, here's 1,000 soms' [roughly $0.85 at the official rate]. Then they called a taxi to take us [to my grandmother's home]."
Judging from Ruzimova's description, their arrival in Uzbekistan was in some ways an improvement over the limbo they endured in a Turkmen detention area.
"They kept us on a grate. I slept on the ground, on the cement," she says. "For the children, they provided a piece of fabric; the children got a mattress, but I slept on the cement."
"We feel sorry for them. The fathers are crying in Turkmenistan, and the children are crying here. We do what we can to help them. We have five families here that are in that situation."
Ruzimova was born in an area along the Turkmen-Uzbek border and married a Turkmen citizen in 1994. At that time, it was fairly easy to travel between the two countries, both former Soviet republics. Many people had family on either side of the border, and conversations are often a mixture of the Uzbek and Turkmen languages.
But crossing the border became more difficult after a purported assassination attempt on Turkmen President Saparmurat Niyazov in November 2002. Despite their efforts to keep up with the bureaucracy, Ruzimova says her marriage and her children's births were never officially registered with the proper Turkmen authorities.
Her children were denied enrollment in school as a result. But then came the deportation of all four children and their mother.
Ruzimova now lives with her grandmother in the Uzbek village of Shavat, and her children are finally attending school.
The grandmother, Aisha Khojaniyazova, laments her granddaughter's decision to marry and live in Turkmenistan: "I am sorry she got married in Turkmenistan. They threw her out with nothing but the dress she was wearing." Not Unique
A man from the same village, who does not want to give his name, says Ruzimova's plight is not unique, not even to the village of Shavat.
"This is not an isolated incident. Our girls are returning," he says. "They started coming back at the beginning of 2006. We feel sorry for them. The fathers are crying in Turkmenistan, and the children are crying here. We do what we can to help them. We have five families here that are in that situation."
Mahmud Tangriberganov heads the local council in the border village of Gozovot, where other young Uzbek women arrived with their children earlier this year after being expelled from Turkmenistan. Tangriberganov says he finds Turkmenistan's policies toward these Uzbek mothers and their children -- who are half-Turkmen -- unbelievable.
"We are against these policies. We don't agree with Turkmenistan's policies," Tangriberganov says. "These are our relatives; these are Uzbeks. And they say that because you are Uzbek, you must leave. Why didn't [the authorities] register their marriages, the births of their children? They could have asked them to pay fines and that way they could have kept the families together, but they didn't do that." Blood And Roots
Turkmenistan's officials have for years sought to emphasize the heritage of the Turkmen nation, sometimes going to absurd lengths to do it. State officials must undergo background checks -- going back three generations -- to verify their lineage.
Under Niyazov, history has been revised to give the Turkmen people a more prominent role in world events. Texts that disagree are increasingly hard to find in Turkmenistan, particularly after the closure of most of the country's libraries.
Critics say the policy appears to imply that other peoples are inferior to Turkmen. And there have already been documented cases of Uzbek children at Turkmen schools being ordered to dress in Turkmen garb or be thrown out.
Turkmen officials have remained silent on the issue of such expulsions, and the seemingly low number of cases means Uzbek officials are likely to continue to avoid the problem. But for broken families like Ziyoda Ruzimova's, the issue can hardly be underestimated.
(Shukrat Babajanov and Khurmat Babadjanov of RFE/RL's Uzbek Service contributed to this report.)