The CIL identifier code is the Production Installation Code for settlement purposes (Spanish: Código de Instalación de producción a efectos de Liquidación). It is the code determined by the person responsible for reading that will uniquely identify a retributive unit of an installation. It shall consist of the Universal Supply Point Code (CUPS) followed by a 3-digit numerical field corresponding to each retributive unit of the installation, starting with the value '001' for the first and so on. For these purposes, CUPS will be common to all the retributive units that an installation may contain. In order to correctly apply the specific remuneration system to an installation, each of its remuneration units must have its own CIL code assigned, wich is different from the other remuneration units in the same installation.