Some navigation objects have a unique identifying name or number that may be shown on the chart. These names are specified by the tag:
where the value is a string that will be rendered adjacent to, or in the middle of, the object in question. The actual name string should be as short as possible, as long names will clutter the map. In most cases the name will be a single word or number. Do not include redundant words such as "buoy" or "light" as this will be obvious from the rendered symbol. Many marks may have an extended reference name or number that appears in port authority lists, but only the part of that number that is unique to that mark should be used for a seamark:name value. An example: "Los Angeles Approach Channel Lighted Buoy 5" should simply be "5" - this is the identifier that is painted on the buoy and is the information that navigators need when determining their position.
Importantly, the seamark:name tag should not be used for positional or object descriptions, object colours or light characteristics.
A complete index to S-100 objects and their OSM tag names: Seamark Objects
A complete index to S-100 attributes and their OSM tag names: Seamark Attributes