ID understanding golf course relations

It is quite common for people to see a golf fairway in iD and click on it expecting to see it properly tagged as a "Fairway" feature type, only to see it as a generic "Line" feature type instead. Thinking that this is wrong, they will then proceed to add a golf=fairway tag, not realizing that they are duplicating information that is already in a more complex representation of multiple objects, expressed as a "relation". With relations (in this case, a multipolygon relation), you can group multiple objects together to represent a single concept. That is, you can say that everything within the outer area is one thing, except for the area inside another object like a green that is a different thing.

You'll notice that when you select the outer ring fairway, that it shows that it is a member of a relation. (See the red arrow in the first screenshot.)

If you then click on that blue "Fairway" link in the left rail, it will expand to show you that the Fairway is defined as the "outer" border, and the "inner" cut-out is the putting green. It would be incorrect to add a `golf=fairway` tag to the outer boundary as that implies that everything inside that boundary is a fairway, including the putting green. The proper place to define the fairway tag is on the relation itself as seen in the second image: