Conceptually, in the urban planning regulations of Spain, the urban qualification consists of the assignment to each land of the uses and their levels of intensity, as well as formal and volumetric characteristics of, where appropriate, the building on that land. This assignment is made by delimiting the land areas that belong to each use and defining it using the appropriate planning instrument.[1]​.

Administratively, the urban qualification is an authorization prior to the municipal license.[2]​.

Defining which instrument is appropriate for qualification is the responsibility in Spain of the autonomous communities, according to the Spanish Constitution of 1978 in its Article 148.3 and the interpretation of this by the jurisprudence established in Sentence 61/1997 of the Constitutional Court") and in Sentence 164/2001 of the Constitutional Court of Spain.[3]​.

A soil can only be classified in two ways: for general uses and for specific uses.[1]​. Rating should not be confused with classification. The regulations consider three classes of land: urbanizable and non-urbanizable (also called "rustic").[1]​ The difference is that in the first two you can build, while in the third you cannot, so buy a rural land and get a reclassification (strictly it would have to say reclassification, but everyone uses reclassification, and the RAE defines as the only meaning of reclassification "change the urban classification of a land»)[4]​ to developable is a big hit.[5]​.