Considerable efforts have been made during the last generation to encourage children and their families to report victimization to authorities. Nonetheless, concern persists that most childhood victimization remains hidden. The 2008 inventory of childhood victimization--the National Study of Children's Exposure to Violence (NatSCEV)--allowed an assessment of whether authorities, including police, school, and medical authorities, are identifying victimizations. The victim, the victim's family, or a bystander may have disclosed the victimization to those authorities, or the authorities may have directly observed the victimization or evidence of that victimization. Among the survey findings: (1) Thirteen percent of children victimized in the previous year had at least one of their victimizations known to police, and 46 percent had one known to school, police, or medical authorities; (2) Authorities knew about a majority of serious victimizations, including incidents of sexual abuse by an adult, they were mostly unaware of other kinds of serious victimizations, such as dating violence and completed and attempted rape; (3) In general, school officials knew about victimization episodes considerably more often (42 percent) than police (13 percent) or medical personnel (2 percent). However, police were the most likely to know about kidnapping, neglect, and sexual abuse by an adult; and (4) More victimization and abuse appears to be known to authorities currently than was the case in a comparable 1992 survey. (Contains 1 table and 2 endnotes.)