r schools: teaching online safety in schools • UK Council for Internet Safety (UKCIS).39 guidance: Education for a connected world • UKCIS guidance: Sharing nudes and semi-nudes: advice for education settings working with children and young people • The UKCIS external visitors guidance will help schools and colleges to ensure the maximum impact of any online safety sessions delivered by external visitors • National Crime Agency's CEOP Education Programme: Protecting children and young people from online child sexual abuse through education 39 UK Council for Internet Safety Education subgroup is made up of sector experts who collaborate to produce advice and guidance to support schools and colleges keep their children safe online. 38 • Public Health England40: Every Mind Matters • Harmful online challenges and online hoaxes - this includes advice on preparing for any online challenges and hoaxes, sharing information with parents and carers and where to get help and support. 133. Whilst it is essential that governing bodies and proprietors ensure that appropriate filtering and monitoring systems are in place, they should be careful that “over blocking” does not lead to unreasonable restrictions as to what children can be taught with regard to online teaching and safeguarding. Online safety 134. It is essential that children are safeguarded from potentially harmful and inappropriate online material. An effective whole school and college approach to online safety empowers a school or college to protect and educate pupils, students, and staff in their use of technology and establishes mechanisms to identify, intervene in, and escalate any concerns where appropriate. 135. The breadth of issues classified within online safety is considerable and ever evolving, but can be categ