Undo & Undelete in Logos 5
Undo (Within a Document)
While working within a document, you can undo an action with CTRL+Z (Mac: Command+Z). This even works when you've deleted an entire note.
Undelete (Entire Documents)
If you delete an entire document, these can be "undeleted" from the Documents menu. Click on "Documents" and select "Undelete Documents" to open the undelete documents page at Logos.com. (You may be asked to sign in first.) From here, you can select your deleted document and send it back to the Logos software with the blue "Undelete" button.