Display overset text frames with plus sign. A text overflow indicator shows when text exceeds the space allocated for it in a text frame (or in the last text frame in the case of threaded text). The indicator is a red box with a plus sign in it.
Setting modifier markOverflowingTextFrames=1 through a URL call marks all the text frames where text is overset with a plus sign. Also, in SPS previewer, the text overset indicator is set to " TRUE " by default.
Default is 0.