One of the allowed types for a property. Is used with the EDIT keyword to specify that the property references a list of other definitions. For example, a Class contains a property called Attributes, which is a list of class attributes. Class attribute is a definition type in of itself, which has its own set of properties. Contrast this to the property of a class called Access Type, which is a list of simple textual choices, such as Public, Private, Protected, and so on. (The LIST command is used to define this simple text list; see LIST.) Also contrast with ONEOF, which specifies that a property references exactly one other definition – an example is that a Class contains a property called Package, which specifies the one package the class resides in; Package is a definition in of itself.
The ASGRID keyword is often used with LISTOF – ASGRID presents the list of definitions in a grid; if it is not used, the definitions are listed in a default list structure. LISTOF is sometimes used with the keyword ZOOMABLE and also COMPLETE (described elsewhere in this chapter). For a LISTOF property, the LENGTH keyword by default is set to 1200. LENGTH specifies how many characters the user may enter in the property field – in this case the total number of characters of the names of definitions that can fit into the list.