How do I add documents to Binders?

To add a document to a binder, follow the steps below.

Open the document from its original location (e.g. Imported drive > AC 91-73B).
Tap the Add Document to Binder button in the upper toolbar.
Tap the binder or binders that the document should be added to. When a document is added to a binder, the binder’s count (e.g., “6 documents”) increases by one, and the checkbox is highlighted.
Once the document has been added to the appropriate binder or binders, tap outside the pop-up menu.