1. Adobe Experience League Documentation, "Use connected cards on a board." This document explicitly states, "You can connect cards to existing Workfront objects, such as tasks or issues. This allows you to manage the work on the card and have the progress automatically update on the connected object." (See the "Overview of connected cards" section).
2. Adobe Experience League Documentation, "Create ad hoc cards on a board." This source clarifies the purpose of ad hoc cards: "You can create ad hoc cards on a board to represent work that is not tied to a Workfront object." This confirms they are not for tracking progress within a project. (See the introductory paragraph).
3. Adobe Experience League Documentation, "Boards overview." This document provides context on the different types of cards: "Cards on a board can be ad hoc cards (standalone cards that are not connected to other Workfront objects) or they can be connected to tasks and issues on projects." (See the "Cards" section).