Conditional Text and InDesign CS4
http://www.layersmagazine.com/conditional-text-and-indesign-cs4.html

White, Terry
Layers Magazine
2009

Abstract:

InDesign has always supported the use of layers, but layers don’t always cut it when working with text. You can put a text frame on a layer and turn that layer on and off as needed, but it’s an all or nothing approach. What if you want to show and hide individual words or paragraphs and have the text automatically rewrap when you show or hide those words? With conditional text, it’s a breeze.