In ABL, you can reference .NET class and interface types (object types) using much the same syntax required for referencing ABL class and interface types (see the Type-name syntax reference entry in ABL Reference). This includes references to unqualified type names with an appropriate USING statement (see Use unqualified .NET type names). You can reference several different supported kinds of .NET classes, including (but not limited to) structures, enumerations, and delegates.

ABL also provides additional syntax support for referencing .NET nested (inner) types, which typically include inner classes or interfaces, and it uses existing syntax to reference .NET array types and .NET generic types. The following sections describe how to reference ABL-supported .NET types that are unique to .NET (do not exist as native ABL object types). For more information on accessing and working with all .NET types supported in ABL, see Use .NET data types in ABL.