.NET Framework 3.0
Specialized collections are collections with highly specific purposes.is based on ; however, NameValueCollection accepts multiple values per key, whereas NameObjectCollectionBase accepts only one value per key.
Some strongly typed collections in thenamespace are and , both of which contain values that are exclusively strings.
Theclass creates instances of case-insensitive collections.
Some collections transform. For example, theclass starts as a and becomes a when it becomes large. The is a list but it also creates a lookup dictionary when the number of elements reaches a specified threshold.