partial and abstract classes

Well, it's a totally different question but, depending on where you want to place the hyperlink, something like this:

Partial classes are marked with the 'partial' keyword and there's normally two or more of them with the same name:

partial class A
{
    // contents
}

partial class A
{
    // the contents will be added to the other partial class, A, at compile time
   //  and compiled as a single class
}

Abstract classes are marked with the 'abstract' keyword:

abstract class B
{
    // contents
}

A class can be both partial and abstract:

abstract partial class C
{
    // contents
}

abstract partial class C
{
    // the contents will be added to the other partial class, C, at compile time
   //  and compiled as a single class
}

Note that 'abstract' must precede 'partial'.