A Category "A" emergency is one which takes place at a nuclear power plant in Canada. For this category of emergency various emergency response plans are used in conjunction with each other to guide response. The FERP (including the National Emergency Response System-Federal Emergency Response Management System and Emergency Support Functions) works with the FNEP, FNEP Provincial Annex and Federal regional emergency response plan. These link to the DFAIT emergency response plan and International arrangements, which in turn link to the CNSC-HQ emergency response plan. This plan links to both the Operator and CNSC on-site nuclear emergency response plan and the Provincial nuclear emergency response plan. These two plans connect to the municipal nuclear emergency response plans. The Provincial nuclear emergency response plan connects to both the Federal regional emergency response plan and the FNEP Provincial Annex.