Reference : 

https://help.sap.com/viewer/d0224eca81e249cb821f2cdf45a82ace/2105/en-US/5e7aa7b0df1d470fb02fdaf267624eb2.html

Script Generator

With the script generator, you can generate a complete export script or a header library.

To start the script generator, log in to Backoffice and navigate to System  Tools  Script Generator. A wizard opens that allows you to generate a complete export script or a header library needed for an Export Wizard started from a search result.

The options available include:

Option	Description/Comment
Script Type	Select the type of the resulting script. You can use Header library only at the wizard open when using the export action on a search result list. It contains only header definitions. Migration generates a whole export script that you can use at the usual export wizard.
Media	References the generated media containing the generated script after clicking the Save button.
Script	The script generated after clicking the Generate button.
Document ID	If enabled, the document ID mechanism is used for references that can not be specified uniquely by using a combination of attributes not equal to PK. If disabled, the PK attribute is used.
Incl. system types	The impex extension adds an attribute system type to the ComposedType type using that you can mark a type as system type. If you enable the flag only for those types, an export statement is generated that is not marked as system type.
Languages	Here you can restrict the languages for which a localized attribute gets an corresponding header attribute. Assume you have 100 languages installed and you select only one. Then only for this single language does each localized attribute get a header attribute generated, otherwise 100 are generated for each.