Binding IEnumerable derived object

This is more of a why question then how.

When I bind a key-value collection to a control, I know to set
DataTextField and DataValueField to key and value. Although I know
how to do this, I can't find where in the MSDN Library this is
documented. I only know this from books and Usenet.

Upon checking objects like Hashtable and ListDictionary via wincv, I
cannot find the properties named key and value, although keys and
values exist.

How does a control find the key and value fields in a collection?
Thanks in advance.