ICT systems can be very varied: warning, monitoring, access control, communications, etc. They often need to be accessed for servicing, or to apply modifications or upgrades. A properly designed and manufactured nameplate can hold a lot of information: system information, serial numbers, service dates, access permission warnings, etc. Another common marking solution is circular steel plates, these can be mounted using ball chains or ties. Narrow nylon ties can also constitute a seal to give visible evidence of tampering.