It's relatively common in JS to use symbols (JSSymbol in Dart terms) as member names. This is often used for interface-like functionality like iterables, disposables, and so on. Currently there's no way to define static JS interop members with symbols as names, which makes it difficult to interact with certain JS idioms. Although it's possible to work around this using dart:js_interop_unsafe, it would be useful to make these definitions possible.