Entity Framework Pitfalls: Collections of Types Other Than ICollection<T> Are Ignored
If you expose in your entity a collection of a type other than ICollection<T> (or one inheriting from it, such as IList<T>) then it will be ignored. This is a bit absurd, because you might want to expose a collection as read only, where you would probably use IEnumerable<T>. For the record, NHibernate allows that.
A possible solution is to have a non-public field of type ICollection<T> and to expose it as an IEnumerable<T> property. The problem is that you won’t be able to use the property in LINQ queries, because it is not mapped. And conventions won’t help either, because you cannot configure collections there.