Typology of content warnings and trigger warnings: Systematic review.

Content and trigger warnings give information about the content of material prior to receiving it. Different typologies of content warnings have emerged across multiple sectors, including health, social media, education and entertainment. Benefits arising from their use are contested, with recent empirical evidence from educational sectors suggesting they may raise anxiety and reinforce the centrality of trauma experience to identity, whilst benefits relate to increased individual agency in making informed decisions about engaging with content. Research is hampered by the absence of a shared inter-sectoral typology of warnings. The aims of this systematic review are to develop a typology of content warnings and to identify the contexts in which content warnings are used. The review was pre-registered (ID: CRD42020197687, URL: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020197687) and used five sources: electronic databases covering multiple sectors (n = 19); table of contents from multi-sectoral journals (n = 5), traditional and social media websites (n = 53 spanning 36 countries); forward and backward citation tracking; and expert consultation (n = 15). In total, 6,254 documents were reviewed for eligibility and 136 documents from 32 countries were included. These were synthesised to develop the Narrative Experiences Online (NEON) content warning typology, which comprises 14 domains: Violence, Sex, Stigma, Disturbing content, Language, Risky behaviours, Mental health, Death, Parental guidance, Crime, Abuse, Socio-political, Flashing lights and Objects. Ten sectors were identified: Education, Audio-visual industries, Games and Apps, Media studies, Social sciences, Comic books, Social media, Music, Mental health, and Science and Technology. Presentation formats (n = 15) comprised: education materials, film, games, websites, television, books, social media, verbally, print media, apps, radio, music, research, DVD/video and policy document. The NEON content warning typology provides a framework for consistent warning use and specification of key contextual information (sector, presentation format, target audience) in future content warning research, allowing personalisation of content warnings and investigation of global sociopolitical trends over time.