Stores a NativeInt integral value as a part of the list.
Tag has no predefined meaning. The Tag property can store any additional integer value for the convenience of developers. Often, Tag stores a pointer. A Tag value can be typecast to the appropriate pointer type. Notice that on 64-bit platforms, all pointer types are 8 bytes in size, while on 32-bit platforms, pointer types are 4 bytes. These pointer sizes correspond to sizes of NativeInt integral values on 64-bit and 32-bit platforms.