The refSNP Summary Record (refSNP Cluster Report). The refSNP Summary Record, also known as the refSNP Cluster Report, provides the user with extensive summary attributes that are supplied by the submitter, calculated by dbSNP from submitted data, or contributed by another NCBI resource. Links within the refSNP summary record direct the user to additional information from any of 20 possible internal and external websites. These linked sites may contain supplementary data that were used in the initial variation call, or may provide detailed phenotypic or clinical assertion data that may suggest variation function. Figures 2A through 2D illustrate the location of the summary attributes as well as the internal and external resource links.