Use Links Efficiently
http://studio.adobe.com/tips/tip.jsp?p=1&id=18&xml=idsn2links
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Adobe

Abstract:

When you place content, Adobe® InDesign® 2.0 doesn't just add the graphics and text to your document—it keeps track of the original files as well. You can use the links to update the data if the original file changes, to track down missing graphic information, or to replace a graphic with another, without losing the transformations you've applied. And when you work with text files, it's usually best to remove the link altogether.