DoNotExposeGenericLists is a Code Analysis rule exposed within Visual Studio when List<T> is publically exposed. For example, List<T> may be exposed through properties, methods, parameters, etc. Why does DoNotExposeGenericLists recommend that I expose Collection instead of List? [David Kean] explains that Collection<T> is the better choice b/c it exposes 4 overidable methods. The methods are ClearItems, InsertItem, RemoveItem and SetItem. Events can be raised from within these four methods to provide a notification when changes are made to the Collection.