NAFO and subsequently adopted in a slightly different format by NEAFC. VMS servers outside of the EU may optionally also use the NAF format due to its widespread use within the EU. Data is usually transmitted using HTTPS protocol either by an HTTP Post or an HTTP Get request. Other protocols such as X.25 have historically been used but are in decline. The NAF format is being replaced by FLUX, which defines messages and forwarding rules for many messages related to various business processes associated with VMS operation. If position reports unexpectedly cease from a vessel, the FMC for the ocean area from which the last signal was received must attempt to contact the vessel or the flag state FMC without delay. Since VMS reports are sent automatically, it is possible that there is nothing wrong with the vessel itself, only the VMS. A full search and rescue (SAR) operation should not be launched simply because a VMS report does not arrive, although it is reasonable to alert sea surveillance assets, such as radars, that might be able to find the vessel. Fishing vessel crews should check the VMS at reasonable intervals, and confirm it is working. While the procedure will vary with the jurisdiction, if an at-sea vessel finds their VMS is not working and they cannot fix it, they may be able to contact the FMC and get permission to continue the voyage. If they do get such authorization, they may get an inspection when they return to port. The FMC may also order them back to port. It is unlikely they will be allowed to leave port again without the VMS being repaired, so that they may need 24/7 VMS technical services at their home port. Position reports received by the FMC should be forwarded automatically to the FMC of the vessel's registry. FMCs and other organizations, such as SAR and research, which receive VMS data must comply with confidentiality agreements. All recipients of data are also in accordance with agreements obliged to handle the data they receive in a responsible manner. Catch documentation scheme Catch reports are not themselves part of VMS, but often will be correlated with VMS data as part of an overall fisheries MCS program. VTS and GMDSS These are specific safety and traffic management systems which generally do not include specific fishery functionality as required by VMS. AIS AIS is often confused