What are the letters and visits with three spans and three separations?

"Three Spans" (across regions, departments and industries) and "Three Separation" (separation of households, households and households).

According to Baidu Encyclopedia, "three spans and three points" are letters and visits, specifically: "three spans" (across regions, departments and industries) and "three points" (household separation, household separation and household separation).

Three spans:

Cross-regional: A case involves two regions, such as immigrants, and may involve domicile and refuge.

Interdepartmental: A case involves two or more departments.

Cross-industry: A case involves two or more industries.

Separation of people: people and things belong to two places. If the complainant has a case in a foreign country, it must be settled at the place where he is registered.

Separation of households: the household registration is inconsistent with the place of residence. Due to urban planning, renovation of dilapidated buildings, housing rental, population mobility and other reasons, the problem of separation between people and households has become increasingly prominent.

Separation of people and households: it is more complicated, and the place where the case occurred, the place of household registration and the place of residence are not together.