If a map symbol is unknown, where should you look for clarification?

The best source for clarification on an unknown map symbol is the marginal data on the map. Marginal data typically includes additional information found around the edges of the map, such as scale, orientation, grid references, and a detailed explanation of map symbols. This typically contains the legend or key that defines symbols used on the map, offering direct clarification for any symbols that may be unfamiliar.

While the legend is an important part of understanding a map, it is often integrated within the broader context of marginal data. Therefore, viewing marginal data can encompass various aspects of the map, including the legend, other explanatory notes, and specific details relevant to that particular map, making it a comprehensive option for clarification.

Local guides or online mapping resources may provide useful information but may not be as immediately accessible or specifically tailored to the map in question compared to the marginal data that is directly associated with the map the user is examining.