rural territory. A propiska could be permanent or temporary. The administrations of hostels, student dormitories, and landlords (very rare case in the USSR, since the "sanitary norm" (a minimum of per person, see below for further details) would usually cause rejection of temporary propiska for such a person) were obliged to maintain temporary propiska records of their guests. The propiska played the role of both residence permit and resident registration of a person. Acquiring a propiska to move to a large city, especially Moscow, was extremely difficult for migrants and was a matter of prestige. Even moving to live with relatives did not automatically provide a person with a permanent propiska because of a minimum area limit () for each resident of a specific apartment. Owing to Soviet property regulations (officially based on the Universal Right to Housing for all), the permanent propiska (which provided the permanent right to dwell in this housing) was nearly impossible for authorities to terminate. The only major exception was a second criminal sentence (after serving the penalty for the first sentence, the inmate returned to the old permanent propiska). If the authorities needed to rule in a certain case, they might refuse a permanent propiska for an individual, but usually not revoking the existing permanent propiska. This also resulted in a situation in which if a spouse agreed (at marriage) to provide the marriage partner with permanent propiska at their apartment, the propiska could not be terminated by divorce, and so exchanging the apartment for two smaller ones was often the only possibility. Sanitary norm Spouses could always provide one another a permanent propiska, but explicit consent was required for this. Children were granted a permanent propiska at one of the parents' permanent propiska locations, and this could not be terminated during the lifetime of the child even as an adult (with the exception of a second criminal sentence), unless the grown-up child voluntarily relocated to another place (and was granted a permanent propiska there). It was not this easy for any other relatives. For such cases, as also for any unrelated people, the so-called "sanitary norm" was used: a propiska would not be issued if it would cause the apartment area to fall below per person. Also, the number of rooms in the apartment was important: two persons of different gender, one or both being 9 years or older, were forbidden to share