Containers are simply channels that generate the majority of their content by executing other channels (or containers). Many of the properties defined for containers pertain to how to gather and arrange content from other channels. For example, properties set in the <Container> definition can describe how to display the contained channels in the container, including: the layout of the container (thin-wide, wide-thin, or thin-wide-thin), a list of the contained channels, the position of the channel (the row and column number), and the window state of the contained channels (maximized, minimized, or detached).
Lower priority display profile documents can overwrite properties of higher priority display profile documents using merge locking. That is, the lock stops the merge on a particular property or value. See Chapter 17, Merge Semantics for a complete discussion of the semantics of the display profile merging.