Final answer:
The CPR number in a tax map key number is used to identify individual units within a larger property, a system important in the administration of real estate in condominiums or similar developments for taxation and transfer purposes.
Step-by-step explanation:
In a tax map key number, the CPR number is used for identifying individual units within a larger property, commonly in the context of condominiums or other developments where there are multiple separate interests within a single piece of land.
The CPR, which stands for Condominium Property Regime, enables real estate to be divided into individual units for ownership purposes while still being part of a larger complex or building. It's crucial for property taxation, sales, and transfers, as each unit may be subject to its own property assessments and transactions.