Objekti, mille ohutust käsitlev dokumentatsioon on ebapiisav, katsetatakse. Dokumentatsioon loetakse ebapiisavaks, kui puudub: ... 2) objekti hooldus-, remondi- või kasutusjuhend ...
In addition to the various functions mentioned, the newest electronic systems automatically transfer calls to alternate numbers, call back the user when busy lines become free, and perform other customer services in response to dialed codes. These systems also perform function tests on their own operations, diagnose problems when they arise, and print out detailed instructions for repairs.