Ellipsometry and polarimetry have enormous capabilities for characterization of multifunctional materials, devices, processing and phenomena at the nanoscale, with consideration of the nanostructure-properties-functionality relationship, which can be addressed non-destructively, non-invasively, in non-contact, in-line and in real-time without any specific condition requirements for measurements and without any sort of environmental impact. This Coordination action is aimed at expressing, assessing and spreading capability of ellipsometry/polarimetry in serving nanomaterial scientists, producers and end-users to address complexity of a large variety of multifunctional nanostructures, hybrid systems, interface behaviours, surface-related phenomena, molecular self-assembling: for all those systems, ellipsometry/polarimetry is beyond just dimension at the nanoscale yielding information on compositional, optical, electrical, magnetic characteristics associated to the specific nanostructure. This CA identify European expertise and establish a platform for (1) coordination of research on ellipsometry for a large variety of nanomaterials, devices and technologies (2) dissemination and development of actions to allow nanomaterials scientists, students, SMEs and end-users approaching and exploiting ellipsometry and polarimetry for designing nanomaterials and nanodevices with unexplored functionalities and for controlling/implementing related production technologies. Advantages that this CA include improvement of knowledge of chemical and physical properties of nanomaterials, new controlled procedures of production, and more sustainable products. The technological impact is huge involving the major production areas and industries of a developed economy such as health-(medicine, biotechnology), environment-(hazardous gas sensing-monitoring), energetics-(photovoltaics), components-(semiconductor, coating industries), which all produce and use multifunctional nanostructure