Genetic varaitns are classified into five different categories based on likelihood of disease. These classifications help differentiate clincial importance of variants and when a genetic variant may be treatable. Additionally genetic teting reports should use international standardized language to ensure accuracy and that the variant can be re-identified in the indivdual in the future or in a relative. This chapter describes the specifics of the nomenclature and reporting languae providers to be able to fully understand the genetic testing reports for their patients.