HtmlSanitizer by Michael Ganss

<PackageReference Include="HtmlSanitizer" Version="6.0.441" />

 RemoveReason

public enum RemoveReason
List of reasons why something was identified to get removed from the HTML
namespace Ganss.XSS { public enum RemoveReason { NotAllowedTag, NotAllowedAttribute, NotAllowedStyle, NotAllowedUrlValue, NotAllowedValue, NotAllowedCssClass, ClassAttributeEmpty, StyleAttributeEmpty } }