Source identification and characterization, catalog contents Catalog contents – issues like “What is the purpose of the catalog?” Derived from the gamma-ray data: Energy bands, source location contours, upper limits, variability index, significance, flux history, spectral index, and source name Test for ‘extendedness’ Correlative – coincidences with sources in selected other catalogs - not source identification or discovery of new source classes, although sources known to be, e.g., pulsars are flagged as such