JA2kz‖Specifies whether content is reduced in size to fit within a text box. Shrinking means that the font size of the content is decreased to fit the content into a text box. The attribute has no effect on boxes where the box content already fits into the box.
To access this command...
t8dFS‖From the context menu:
J3aWQ‖Select a text box and choose Shrink text on overflow.