YAMPAT allows you to easily add references to your packs. References can be added from the Management Pack Manifest dialog. Navigate to the Management Pack menu and click Manifest.
YAMPAT automatically includes references for whatever version of Operations Manager you select when creating or opening a Management Pack.
To reference any Management Packs from the Manifest dialog, you need to add them to a Custom Store using the Store Manager.
Visual Studio Authoring Extensions includes base packs for several versions of SCOM and are automatically included in the store.
The Store Manager is quite simply a list of directories in which you can populate with .mp or .mpb (Management Pack Bundle) files. If a .mp or .mpb file is in one of the directories listed, it will be available to be added as a reference to your Management Pack.
This is also required if you want to create management packs for Linux or Unix.
You can access the Store Manager from the Tools menu. Add any directories you see fit for your environment. Even packs that you create with YAMPAT can be added!
The only requirement here is that any Management Pack added to a store directory must be unique across all stores or you will get an error when opening a Management Pack that references that duplicate pack.