Data Validation Annotations You Won't See In .NET 5.0

I just heard today - the attributes demonstrated below didn't make the cut.

public class EditViewModel
{
    [GoodLooking]
    [NotATerrorist]
    public User CurrentUser { get; set; }  

    [ProperGrammer]
    [Profanity(ProfanityLevel.None)]
    public string Description { get; set; }
}