On top of the features of Add/Edit Doc explained on Designer Guide, Admin should additionally manage the notion of plugins (plugin and componentXid).
Add Doc
set plugin
Thus, for example, creating new doc: fill all the fields and choose the correct plugin to connect that doc to (as shown on the image below):
choose the plugin
Note: Only plugins that are editable on that platform will be shown!
set componentXid
Once the plugin is set (ex. fw.demo), the componentXid could be set by ADMIN. The componentXid should be one string. Good practice is to connect words by using the underscore ''. (ex: demo_doc). The doc could be now saved by clicking on Save button: