Naming conventions for the only envisioned implementation of an interface [closed]

Question

If you decide "Program to An Interface" trumps YAGNI and decide to create a supertype where you don't envision anything other than one obvious implementation - is there a convention for naming the obvious concrete type? E.g. this morning I wrote a a class called PlainOldConversionReport and I wonder if that name betrays ignorance of convention. Would there a more normal name, in Object Oriented development generally or .Net or C# specifically, to give to a non specialized subtype of IConversionReport?