To
use a path or text frame as a graphics placeholder frame, select
a path or an empty text frame, and then choose Object >
Content > Graphic.
To use a path or graphics frame as a text placeholder
frame, select a path or an empty graphics frame, and then choose
Object > Content > Text.
To use a text or graphics frame as a path only, select
an empty frame, and then choose Object > Content >
Unassigned.
Note: When a frame contains text or graphics, you cannot
redefine it using the Object > Content menu. However,
the frame automatically redefines itself if you select it and replace
its contents.