I have been participating in a small conversation (In dansih) about creating your own configuration section and having arrays in that section.
So I stated that you can make your own config section and have arrays in it.
Here is the code to prove it.
Update:
OK, so according to "the official definition of array" it is a datastructure, that can be accesed by indexing.
Well since this is xml it is a pure datarepresentation, hence you can not access it by an index until you hydrate it into a programming environment.
So strictly speaking this is not an array.
But as soon as you use it in .Net, or some kind of XPath expression tool, you get an array