The population without double counting (PSDC) includes :
- the population of dwellings, including school boarders and military personnel staying in an establishment of another municipality and having their personal residence in the municipality ;
- the population of the collective establishments in the municipality: workers in a home, students in a hall of residence, senior citizens in a home, long term hospital patients, monks, nuns, persons in a short or long term accommodation centre, others including handicapped persons, etc ;
- the homeless or people living in mobile accommodation and boatmen ;
- the population of the prisons of the municipality ;
- military personnel and school boarders living in the municipality and not having any other residence.
The concept of population without double counting is used to calculate the population of a set of municipalities where each person is counted only once. This is the case, for example, for the population of a department. This notion is not any more effective at present, it was until the last publishing of the general census of the population of 1999.