The 2018 Common Alerting Protocol (CAP) Implementation Workshop was held 31 October – 1 November, in Hong Kong, China. The host of this Workshop was Hong Kong Observatory (HKO). CAP Implementation Workshops focus on emergency alerting as enabled by the CAP standard, ITU-T Recommendation X.1303. At the Workshops, implementors of CAP and associated organizations discuss common issues and how best to expand adoption of CAP.