AngleSharp by Florian Rappl

<PackageReference Include="AngleSharp" Version="0.8.4.1" />

 PseudoElementNames

static class PseudoElementNames
The collection of (known / used) selector pseudo element names.
namespace AngleSharp.Css { internal static class PseudoElementNames { public static readonly string Before = "before"; public static readonly string After = "after"; public static readonly string Selection = "selection"; public static readonly string FirstLine = "first-line"; public static readonly string FirstLetter = "first-letter"; } }