Prefixing abstract classes with "A" like interfaces are prefixed with "I"?

Question

It seems to me that it'd be useful to be able to tell at a glance that a class is abstract and not meant to be directly instantiated just like it's useful to be able to easily identify an interface.

My question is, why didn't "AFourLeggedAnimal : IAnimal" catch on? Is it simply because of the possible confusion (which I just noticed while writing that) for example confusing it as "A four legged animal" instead of "abstract class FourLeggedAnimal"? Or is it something more?

Coming from Java in school to C# at work, I found the "I" prefix naming convention extremely useful when glancing through a list of classes and it seems to me that it'd be convenient to be able to distinguish between concrete and non-concrete classes at a glance without needing to look at the code.

Answer 1

Use the suffix "Base" as Joel mentions. Once you have a lot in your project, it's pretty easy to tell apart:

public abstract AnimalBase
{
  public AnimalType AnimalType { get; set; }
}

public abstract HorseBase : AnimalBase
{
  public HoovesManufacturer HoovesManufacturer { get; set; }
}

public class Pony : HorseBase
{
  public Pony()
  {
  }
}