Class notations (DNV, ABS, etc.)

Class notations are coded symbols a classification society assigns to a ship to record its type, service, and the optional rule sets it meets. Each society uses its own syntax, but the structure is shared: a character of classification or main class mark (for example DNV 1A1, ABS A1) confirms the hull and machinery were built and are maintained to class rules, followed by service notations (Bulk Carrier, Oil Tanker, Container Ship), and additional or descriptive notations for ice class, redundancy, coatings, or environmental class (DNV CLEAN, ABS ENVIRO). Notations drive survey scope, port and charter acceptance, and insurance, so they are checked at every periodical survey.