For example, for System.System.Text.RegularExpressions.RegexOptions:


FSharpFields is used to create custom tooltips in MonoDevelop (and I'm trying to port it to VS Code at the moment) https://github.com/mono/monodevelop/blob/8b17d75ff2dc26c5aa1a6246f6a2ce7d4f65e3be/main/external/fsharpbinding/MonoDevelop.FSharpBinding/FSharpSymbolHelper.fs#L681-L689
As FSharpFields are empty, both MonoDevelop and Code show the following tooltip:


Currently we use FSharpCheckFileResults.GetToolTipTextAlternate https://github.com/fsharp/FSharp.Compiler.Service/blob/master/src/fsharp/vs/service.fs#L1909 and it does show enum fields properly:
