Allows the creation of user-defined types out of the existing types. The defined type can then be used multiple times independently. This is especially useful in conjunction with the “include” functionality because types can be defined in the included APL script, and then used where necessary in the template. Note that define doesn’t take a as an argument. the keyword “define” is followed by a type definition such as choice. When prefaced with “define” the elements name becomes the new type which can be used later.